United States

Department of

Agriculture

Animal and

Plant Health

Inspection

Service

Veterinary

Services

National

Animal Health

Monitoring

System

March 2007

Dairy 2007

Part II: Changes in the U.S. Dairy Cattle

Industry, 1991–2007
Mention of companies or commercial products does

not imply recommendation or endorsement by the

USDA over others not mentioned. USDA neither

guarantees nor warrants the standard of any product

mentioned. Product names are mentioned solely to

report factually on available data and to provide

specific information.

USDA:APHIS:VS:CEAH

NRRC Building B, M.S. 2E7

2150 Centre Avenue

Fort Collins, CO 80526-8117

970.494.7000

E-mail: NAHMS@aphis.usda.gov

http://nahms.aphis.usda.gov

#N481.0308

The U.S. Department of Agriculture (USDA) prohibits

discrimination in all its programs and activities on the

basis of race, color, national origin, age, disability, and

where applicable, sex, marital status, familial status,

parental status, religion, sexual orientation, genetic

information, political beliefs, reprisal, or because all or

part of an individual’s income is derived from any public

assistance program. (Not all prohibited bases apply to

all programs.) Persons with disabilities who require

alternative means for communication of program

information (Braille, large print, audiotape, etc.) should

contact USDA’s TARGET Center at (202) 720–2600

(voice and TDD). To file a complaint of discrimination,

write to USDA, Director, Office of Civil Rights, 1400

Independence Avenue, S.W., Washington, D.C.

20250–9410, or call (800) 795–3272 (voice) or (202)

720–6382 (TDD). USDA is an equal opportunity

provider and employer.

Cover photo courtesy of

Dr. Jason Lombard
USDA APHIS VS / i

Acknowledgments

This report has been prepared from material received and analyzed by the U.S.

Department of Agriculture (USDA), Animal and Plant Health Inspection Service

(APHIS), Veterinary Services (VS) via four national studies of health

management and animal health on U.S. dairy operations conducted between

1991 and 2007.

The 1991 National Dairy Heifer Evaluation Project, Dairy 1996, Dairy 2002, and

Dairy 2007 were cooperative efforts between State and Federal agricultural

statisticians, animal health officials, university researchers, and extension

personnel. We want to thank the National Agricultural Statistics Service (NASS)

enumerators, State and Federal veterinary medical officers (VMOs), and animal

health technicians (AHTs) who visited the farms and collected the data. Their

hard work and dedication to the National Animal Health Monitoring System

(NAHMS) are invaluable. The roles of the producer, Area Veterinarian in Charge

(AVIC), NAHMS Coordinator, VMOs, AHTs, and NASS enumerators were critical

in providing quality data for Dairy 2007 reports. Thanks also to the personnel at

the Centers for Epidemiology and Animal Health (CEAH) for their efforts in

generating and distributing valuable reports from Dairy 2007 data.

Additional biological sampling and testing were afforded by the generous

contributions of collaborators for the Dairy 2007 study, including:

• USDA-APHIS, National Veterinary Services Laboratories

• USDA-ARS, Beltsville Agricultural Research Center

• USDA-ARS, Russell Research Center

• Antel BioSystems, Inc.

• Cornell University Animal Health Diagnostic Laboratory

• Quality Milk Production Services

• Tetracore, Inc

• University of Pennsylvania, New Bolton Center

• University of Wisconsin, Madison

• Wisconsin Veterinary Diagnostic Laboratory

All participants are to be commended, particularly the producers whose voluntary

efforts made the Dairy 2007 study possible.

Larry M. Granger

Director

Centers for Epidemiology and Animal Health
ii / Dairy 2007

Suggested bibliographic citation for this report:

USDA. 2008. Dairy 2007, Part II: Changes in the U.S. Dairy Cattle Industry,

1991–2007

USDA-APHIS-VS, CEAH. Fort Collins, CO

#N481.0308

Contacts for further information:

Questions or comments on data analysis: Dr. Jason Lombard (970) 494-7000

Information on reprints or other reports: Ms. Kathy Snover (970) 494-7000

E-mail: NAHMS@aphis.usda.gov
USDA APHIS VS / iii

Table of Contents

Introduction 1

Terms Used In This Report 3

Section I: Historical Changes in the U.S. Dairy Industry 4

A. General Trends 4

1. Milk cow inventory 4

2. Number and size of dairy operations 8

3. Milk production 12

4. Bulk-tank somatic cell counts 16

5. Milk prices 18

6. Milk cow prices 21

7. Dairy cow slaughter 22

8. Value of production 23

B. Dairy Industry Changes by State 24

1. Milk cow inventory 24

2. Number of U.S. dairy operations 26

3. U.S. average dairy herd size 29

4. Milk production per cow 30

Section II: Changes in World Dairy Production 32

General Trends 32

1. Milk cow inventory 32

2. Milk production 33

Section III: Management, NAHMS Population Estimates 34

A. Dairy Herd Information 34

1. Record-keeping systems 34

2. Identification 36

3. Breed of dairy cows 38

4. Cow registration 38

5. Quality assurance programs 39

B. Productivity 40

1. Rolling herd average milk production 40

2. Age at first calving 41

3. Days dry 42

4. Calving interval 42

C. Heifer Management 44

1. Source of heifers 44

2. Separation from dam 44

3. Colostrum 45

4. Medicated milk replacer 49

5. Weaning age 50

6. Preventive practices 52

7. Vaccination practices 54

8. Types of BVD vaccine 56
iv / Dairy 2007

D. Heifer Health 57

1. Calves born alive 57

2. Mortality 57

3. Carcass disposal 62

E. Cow Management 63

1. Home-raised replacements 63

2. Housing 63

3. Milking facilities 64

4. Nutrition 66

5. Number of bulls 68

6. Preventive practices 68

7. Vaccination practices 70

8. Types of BVD vaccine 72

9. Bovine somatotropin (bST) 73

F. Cow Health 74

1. Abortions 74

2. Cow morbidity 75

3. Permanently removed cows 77

4. Mortality 78

5. Carcass disposal 80

G. Biosecurity 81

1. Physical contact with unweaned calves 81

2. Physical contact with other animals 82

3. Biosecurity for new arrivals 84

4. Quarantine 84

5. Vaccine requirements 86

6. Testing requirements 88

Appendix I: Methodology Overview 91

Appendix II: Study Objectives and Related Outputs 92
Introduction

USDA APHIS VS / 1

Introduction

In 1983, promoters of the concept that would become the USDA’s National

Animal Health Monitoring System (NAHMS) envisioned a program that would

monitor changes and trends in national animal health and management. They

hoped to provide periodic snapshots of U.S. food animal industries. With these

industry overviews, members could identify opportunities for improvement,

provide changing foundations for research and special studies, and detect

emerging problems.

Section I of this report shows demographic changes of the U.S. dairy industry

from a historical perspective using data provided by the USDA’s National

Agricultural Statistics Service (NASS) and Agricultural Marketing Service (AMS).

Section II shows demographic changes of the world dairy industry using data

provided by USDA’s Foreign Agricultural Service (FAS). Results of four NAHMS

national studies in Section III complete the overview of change in the U.S. dairy

industry during the 16-year period of 1991 to 2007.

NAHMS’ first national study of the U.S. dairy industry, the 1991 National Dairy

Heifer Evaluation Project (NDHEP), provided the snapshot of animal health and

management that would serve as a baseline from which to measure industry

changes in animal health and management. NAHMS’ Dairy 1996, Dairy 2002,

and Dairy 2007 studies have fulfilled the vision of the program’s founding

objective, monitoring the trends in national animal health and management

practices.

The NDHEP 1991 included herds of 30 or more milk cows and heifer-rearing

operations in 28 States representing 83 percent of U.S. milk cows. Dairy 1996

described dairy production for operations with one or more milk cows in 20

States representing 83 percent of the Nation’s milk cows. Dairy 2002 described

dairy production for operations with one or more milk cows in 21 States

representing 85 percent of the Nation’s dairy cows. Dairy 2007 was conducted in

17 of the Nation’s major dairy States and provides information representing 80

percent of U.S. dairy operations and 83 percent of U.S. dairy cows. This report,

Part II: Changes in the United States Dairy Industry, 1991-2007, provides

national estimates of animal health management practices for comparable

populations from all four studies. Reports from all four NAHMS dairy studies—

including the studies’ methodologies—are available at http://

nahms.usda.aphis.gov.
Introduction

2 / Dairy 2007

Further information on NAHMS studies and reports is available at:

http://nahms.aphis.usda.gov.

For questions about this report or additional copies, please contact:

USDA-APHIS-VS-CEAH

NRRC Building B, M.S. 2E7

2150 Centre Avenue

Fort Collins, CO 80526-8117

970.494.7000

States Participating in NAHMS Dairy Studies, 1991, 1996, 2002, 2007

1 = NDHEP 1991

2 = Dairy 1996

3 = Dairy 2002

4 = Dairy 2007

1,2,3,4

1,2

1,2,3,4

1,2,3,4

1,3

2,3,4

1

2,3,4

1,2,3,4

1,2,3,4

2,3,4

1,2,3

1,2,3,4

1,2,3

1,2,3,4

1,2

3,4

1,2,3,4

1,2,3,4

1,2,3,4

1,2,3,4

1

1,3,4

1

1 1

1,2,3

2,3,4

1
USDA APHIS VS / 3

Introduction

Terms Used In

This Report

Cow: Female dairy bovine that has calved at least once.

Cow average: The average value for all cows; the reported value for each

operation multiplied by the number of cows on that operation is summed over all

operations and divided by the number of cows on all operations. This way, the

result is adjusted for the number of cows on each operation. For instance, on

p 41 the cow average age at first calving is multiplied by the number of cows for

each operation. This product is then summed over all operations and divided by

the sum of cows over all operations. The result is the average age at first calving

for all cows.

Dairy Herd Improvement Association (DHIA): An organization with programs

and objectives intended to improve the production and profitability of dairy

farming. DHIA also aids farmers in keeping milk production and management

records.

Heifer: Female dairy bovine that has not yet calved.

Herd size: Herd size is based on January 1 respective inventories. Small herds

are those with fewer than 100 head; medium herds are those with 100 to 499

head; and large herds are those with 500 or more head.

NA: Not available.

Operation average: A single value for each operation is summed over all

operations reporting divided by the number of operations reporting. For instance,

operation average age at first calving (shown on p 41) is calculated by summing

reported average age over all operations divided by the number of operations.

Population estimates: Estimates in this report are provided with a measure of

precision called the standard error. A 95-percent confidence interval can be

created with bounds equal to the estimate, plus or minus two standard errors. If

the only error is sampling error, the confidence intervals created in this manner

will contain the true population mean 95 out of 100 times. In the example to the

left, an estimate of 7.5 with a standard error of 1.0 results in limits of 5.5 to 9.5

(two times the standard error above and below the estimate). The second

estimate of 3.4 shows a standard error of 0.3 and results in limits of 2.8 and 4.0.

Alternatively, the 90-percent confidence interval would be created by multiplying

the standard error by 1.65 instead of 2. Most estimates in this report are rounded

to the nearest tenth. If rounded to 0, the standard error was reported. If there

were no reports of the event, no standard error was reported.

Rolling Herd Average (RHA): Average milk production per cow (lb/cow) in the

herd during the previous 12 months.
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

4 / Dairy 2007

Section I: Historical Changes in the U.S. Dairy Industry

A. General Trends

1. Milk cow inventory

On January 1, 2007, U.S. milk cows numbered 9,129,000 head, 94.4 percent of

the 9,672,000 milk cows in 1870. All U.S. cattle and calves numbered 97,002,900

head in 2007, about three times the number of cattle and calves in 1870

(31,082,000 head).

a. Long-term changes in U.S. milk cow January 1 inventory, 1870-2007:

 Milk Cows 

All Cattle 

and Calves 

Year 1,000 Head

Percent of 

1870

Percent of All 

Cattle and 

Calves 1,000 Head 

1870 9,672.0 100.0 31.1 31,082.0 

1880 11,754.0 121.5 27.1 43,347.0 

1890 15,000.0 155.1 25.0 60,014.0 

1900 16,544.0 171.1 27.7 59,739.0 

1910 19,450.0 201.1 33.0 58,993.0 

1920 21,455.0 221.8 30.5 70,400.0 

1930 23,032.0 238.1 37.8 61,003.0 

1940 24,940.0 257.9 36.5 68,309.0 

1950 23,853.0 246.6 30.6 77,963.0 

1960 19,527.0 201.9 20.3 96,236.0 

1970 12,090.7 125.0 10.8 112,368.7 

1980 10,758.2 111.2 9.7 111,242.4 

1990 10,014.8 103.5 10.5 95,816.2 

2000 9,182.8 94.9 9.4 98,199.0 

2007 9,129.0 94.4 9.4 97,002.9 

Note: Unless otherwise noted, tables in this section are comprised from

data collected by USDA’s National Agricultural Statistics Service (NASS).
USDA APHIS VS / 5

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

6 / Dairy 2007

The number of milk cows that calved each year decreased about 6 percent from

1992 to 2002 but remained stable from 2002 to 2007.

b. Recent changes in U.S. milk cow January 1 inventory, 1992-2007:

Milk Cows 

Year 1,000 Head 

Percent 

Previous 

Year 

Percent of 

1992 

Percent of 

1996 

Percent of 

2002 

1992 9,728.2 97.6 100.0 -- -- 

1993 9,658.1 99.3 99.3 -- -- 

1994 9,507.0 98.4 97.7 -- -- 

1995 9,481.8 99.7 97.5 -- -- 

1996 9,419.9 99.3 96.8 100.0 -- 

1997 9,317.9 98.9 95.8 98.9 -- 

1998 9,199.0 98.7 94.6 97.7 -- 

1999 9,128.0 99.2 93.8 96.9 -- 

2000 9,182.8 100.6 94.4 97.5 -- 

2001 9,171.7 99.9 94.3 97.4 -- 

2002 9,105.6 99.3 93.6 96.7 100.0 

2003 9,141.7 100.4 94.0 97.0 100.4 

2004 8,989.5 98.3 92.4 95.4 98.7 

2005 9,005.0 100.2 92.6 95.6 98.9 

2006 9,062.9 100.6 93.2 96.2 99.5 

2007 9,129.0 100.7 93.8 96.9 100.3 
USDA APHIS VS / 7

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

The January 1, 2007, number of replacement heifers has increased 4.3 percent

since 1992. Replacement heifers as a percentage of the milk cow inventory

remains between 42.5 and 47.2 percent, with recent years showing the larger

percentage.

c. Recent changes in U.S. replacement heifer January 1 inventory, 1992-2007:

Milk Cow Replacement Heifers 

Year 1,000 Head 

Percent 

Previous 

Year 

Percent of 

1992 

Percent 

of 1996 

Percent 

of 2002 

Percent of 

Milk Cows 

1992 4,131.4 100.9 100.0 -- -- 42.5 

1993 4,176.2 101.1 101.1 -- -- 43.2 

1994 4,124.5 98.8 99.8 -- -- 43.4 

1995 4,121.3 99.9 99.8 -- -- 43.5 

1996 4,090.3 99.2 99.0 100.0 -- 43.4 

1997 4,058.4 99.2 98.2 99.2 -- 43.6 

1998 3,985.7 98.2 96.5 97.4 -- 43.3 

1999 4,068.8 102.1 98.5 99.5 -- 44.6 

2000 3,999.8 98.3 96.8 97.8 -- 43.6 

2001 4,057.0 101.4 98.2 99.2 -- 44.2 

2002 4,054.8 99.9 98.1 99.1 100.0 44.5 

2003 4,113.9 101.5 99.6 100.6 101.5 45.0 

2004 4,020.0 97.7 97.3 98.3 99.1 44.7 

2005 4,118.3 102.4 99.7 100.7 101.6 45.7 

2006 4,275.0 103.8 103.5 104.5 105.4 47.2 

2007 4,309.9 100.8 104.3 105.4 106.3 47.2 
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

8 / Dairy 2007

2. Number and size of dairy operations

Approximately 4 to 7 percent of dairy operations have gone out of business each

year since 1991. Since 1991, the number of dairy operations decreased by 58.4

percent, while milk cow numbers in 2007 were at 93.8 percent of 1992 numbers.

In this time frame, milk per cow increased by 32.7 percent and total milk

production increased by 23.1 percent.

a. Recent changes in the number of U.S. dairy operations*, 1991-2006:

Year 

Number of 

Operations 

Percent 

Previous 

Year 

Percent of 

1991 

Percent of 

1995 

Percent of 

2001 

1991 180,640 93.8 100.0 -- -- 

1992 170,500 94.4 94.4 -- -- 

1993 157,150 92.2 87.0 -- -- 

1994 148,140 94.3 82.0 -- -- 

1995 139,670 94.3 77.3 100.0 -- 

1996 130,980 93.8 72.5 93.8 -- 

1997 123,700 94.4 68.5 88.6 -- 

1998 117,145 94.7 64.8 83.9 -- 

1999 110,855 94.6 61.4 79.4 -- 

2000 105,055 94.8 58.2 75.2 -- 

2001 97,460 92.8 54.0 69.8 100.0 

2002 91,240 93.6 50.5 65.3 93.6 

2003 86,360 94.7 47.8 61.8 88.6 

2004 81,520 94.4 45.1 58.4 83.6 

2005 78,300 96.1 43.3 56.1 80.3 

2006 75,140 96.0 41.6 53.8 77.1 

* An operation is any place having one or more milk cows—excluding cows used to nurse calves—

on hand any time during the year. 
USDA APHIS VS / 9

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

10 / Dairy 2007

The percentage of operations with fewer than 50 cows has decreased since

1991, while the percentage of operations with more than 100 head has increased

every year since 1991. More than 1 in 10 operations (11.5 percent) had more

than 100 cows in 1991 compared to about 2 in 10 (23.3 percent) in 2006.

b. Percentage of U.S. dairy operations by herd size, 1991-2006:

Percent Operations 

Herd Size (Number of Cows) 

Year 1-29 30-49 50-99 100-199 200-499 500+ 

1991 39.8 22.8 25.9 11.51 

1992 38.9 22.1 26.0 13.01 

1993 37.3 22.2 26.8 9.3 4.42

1994 36.1 22.0 27.4 9.8 4.72

1995 34.5 22.2 28.1 10.2 5.02

1996 32.9 22.3 28.7 10.7 5.42

1997 31.6 22.1 29.0 11.3 4.1 1.9 

1998 30.8 21.8 29.1 11.9 4.4 2.0 

1999 29.7 21.7 29.6 11.9 4.8 2.3 

2000 29.3 21.2 29.7 12.2 5.1 2.5 

2001 29.0 20.4 29.8 12.6 5.3 2.9 

2002 28.9 19.8 30.0 12.6 5.5 3.2 

2003 29.0 19.5 29.9 12.7 5.5 3.4 

2004 29.2 19.0 29.5 12.8 5.8 3.7 

2005 28.7 19.0 29.6 12.8 6.0 3.9 

2006 28.3 18.8 29.6 13.0 6.1 4.2 

1

These estimates include herds of 100 or more head. 

2

These estimates include herds of 200 or more head.
USDA APHIS VS / 11

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

Operations with more than 200 cows accounted for 61.7 percent of cows in 2006

compared to 31.8 percent in 1993.

c. Percentage of U.S. milk cow inventory by herd size, 1991-2006:

 Percent Inventory 

Herd Size (Number of Cows) 

Year 1-29 30-49 50-99 100-199 200-499 500+ 

1991 6.3 16.6 31.7 45.41

1992 5.5 15.2 30.0 49.31

1993 5.0 14.8 29.2 19.2 31.82

1994 4.6 14.0 28.7 19.3 33.42

1995 4.0 13.0 28.0 20.0 35.02

1996 4.0 12.0 27.0 20.0 37.02

1997 3.5 11.5 26.0 20.0 14.6 24.4 

1998 3.6 10.5 24.3 19.3 15.5 26.8 

1999 3.2 10.2 23.3 18.4 16.3 28.6 

2000 2.9 9.1 22.0 18.1 16.6 31.3 

2001 2.7 8.0 20.8 17.2 16.3 35.0 

2002 2.4 7.4 19.6 16.4 15.9 38.3 

2003 2.3 6.9 18.8 15.7 15.4 40.9 

2004 2.1 6.6 17.8 15.1 15.5 42.9 

2005 2.0 6.4 17.1 14.6 15.4 44.5 

2006 1.9 6.0 16.3 14.1 15.0 46.7 

1

These estimates include herds of 100 or more head. 

2

These estimates include herds of 200 or more head.
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

12 / Dairy 2007

3. Milk production

Milk production per cow has increased as much as 1 to 3 percent annually since

1991, with the exception of 2001. Milk production per cow was 19,951 pounds in

2006 compared to 15,031 pounds in 1991—a 32.7-percent increase.

a. Recent changes in U.S. milk production per cow, 1991-2006:

 Milk per Cow 

Year 

Average 

Number of 

Milk Cows* 

(1,000 

Head) 

Pounds 

per Cow 

Percent 

Previous 

Year 

Percent of 

1991 

Percent of 

1995 

Percent of 

2001 

1991 9,826 15,031 101.7 100.0 -- -- 

1992 9,688 15,570 103.6 103.6 -- -- 

1993 9,581 15,722 101.0 104.6 -- -- 

1994 9,494 16,179 102.9 107.6 -- -- 

1995 9,466 16,405 101.4 109.1 100.0 -- 

1996 9,372 16,433 100.2 109.3 100.2 -- 

1997 9,252 16,871 102.7 112.2 102.8 -- 

1998 9,151 17,185 101.9 114.3 104.8 -- 

1999 9,153 17,763 103.4 118.2 108.3 -- 

2000 9,199 18,197 102.4 121.1 110.9 -- 

2001 9,103 18,162 99.8 120.8 110.7 100.0 

2002 9,139 18,608 102.5 123.8 113.4 102.5 

2003 9,083 18,760 100.8 124.8 114.4 103.3 

2004 9,012 18,967 101.1 126.2 115.6 104.4 

2005 9,043 19,565 103.2 130.2 119.3 107.7 

2006 9,112 19,951 102.0 132.7 121.6 109.9 

*Average number during the year, excluding heifers not yet fresh. 
USDA APHIS VS / 13

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

14 / Dairy 2007

Total milk production in the United States has increased more than 20 percent

since 1991, despite an approximate 6-percent drop in the number of cows. In

2006, total milk production was 181,798 million pounds compared to 147,697

million pounds in 1991.

b. Recent changes in U.S. total milk production, 1991-2006:

Total Milk Production 

Year 

Total Milk* 

(Million 

Pounds) 

Percent 

Previous 

Year 

Percent of 

1991 

Percent of 

1995 

Percent of 

2001 

1991 147,697 100.0 100.0 -- -- 

1992 150,847 102.1 102.2 -- -- 

1993 150,636 99.8 102.0 -- -- 

1994 153,602 102.0 104.0 -- -- 

1995 155,292 101.1 105.1 100.0 -- 

1996 154,006 99.2 104.3 99.2 -- 

1997 156,091 101.4 105.7 100.5 -- 

1998 157,262 100.8 106.5 101.3 -- 

1999 162,589 103.4 110.1 104.7 -- 

2000 167,393 103.0 113.3 107.8 -- 

2001 165,332 98.8 111.9 106.5 100.0 

2002 170,063 102.9 115.1 109.5 102.9 

2003 170,394 100.2 115.4 109.7 103.1 

2004 170,934 100.3 115.7 110.1 103.4 

2005 176,929 103.5 119.8 113.9 107.0 

2006 181,798 102.8 123.1 117.1 110.0 

*Excluding milk nursed by calves.
USDA APHIS VS / 15

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

16 / Dairy 2007

4. Bulk-tank somatic cell counts

Bulk tank somatic cell counts (BTSCCs) from 4 of the 10 U.S. Federal Milk

Marketing Orders were analyzed from 1995 to 2006. Monthly BTSCCs were

weighted based on the pounds of milk shipped, and, subsequently, a geometric

mean of all milk-weighted somatic cell counts was calculated. BTSCCs from the

four Federal Milk Marketing Orders have decreased over the last 12 years.

Typically, BTSCCs spike during summer months and decline quickly during fall.

BTSCCs have ranged from a high of 384,100 in August 1995 to a low of 234,200

in March 2006. Beginning in 2004, BTSCCs have decreased in January through

July for each subsequent year.

a. Milk-weighted bulk tank somatic cell counts from Federal Milk Marketing

Orders, 1995–2006* (January through June):

Bulk Tank Somatic Cell Counts (x1,000 cells/ml), 1995–2006 

 Month (January–June)

Year January February March April May June 

1995 298.8 293.2 297.0 289.3 286.1 308.6 

1996 275.5 283.5 283.3 277.0 280.4 309.2 

1997 288.2 294.9 295.9 291.3 293.4 299.9 

1998 284.4 280.2 282.4 282.6 284.2 298.6 

1999 278.5 288.8 282.8 283.9 286.4 315.3 

2000 258.0 279.9 283.7 282.5 292.6 311.9 

2001 286.5 280.2 281.7 284.5 291.6 305.9 

2002 283.4 281.8 279.1 279.5 270.9 284.9 

2003 274.4 279.9 281.0 271.5 277.6 292.2 

2004 250.0 257.6 266.3 264.4 260.5 274.7 

2005 246.7 248.2 243.8 244.9 245.5 264.3 

2006 240.8 234.7 234.2 236.4 234.7 249.1 

*Agricultural Marketing Service data summarized by NAHMS. 
USDA APHIS VS / 17

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

b. Milk-weighted bulk tank somatic cell counts from Federal Milk Marketing

Orders, 1995–2006* (July through December):

 Bulk Tank Somatic Cell Counts (x1,000 cells/ml), 1995–2006 

 Month (July–December) 

Year July August September October November December 

1995 342.8 384.1 356.4 296.6 267.7 265.2 

1996 338.7 334.1 313.0 275.6 265.3 285.4 

1997 330.3 336.7 314.1 276.9 257.0 269.3 

1998 330.2 328.4 312.3 288.2 278.2 272.7 

1999 341.4 363.7 325.5 282.4 263.6 259.3 

2000 334.2 341.4 326.4 287.4 280.4 280.5 

2001 332.5 352.5 327.3 288.1 278.7 282.6 

2002 328.0 340.1 318.0 287.0 273.6 267.2 

2003 317.8 323.7 304.1 270.3 252.0 251.2 

2004 294.5 293.6 270.4 247.9 240.9 239.5 

2005 286.8 296.1 281.7 258.9 242.5 240.1 

2006 267.1 296.9 280.3 253.0 235.4 239.4 

*Agricultural Marketing Service data summarized by NAHMS. 

220

240

260

280

300

320

340

360

380

400

 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06

Year

BTSCC X 1,000

Monthly milk-weighted bulk tank somatic cell counts from Federal Milk

Marketing Orders, 1995–2006
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

18 / Dairy 2007

5. Milk prices

From 1991 through 2006, milk prices paid to producers ranged from a low of

$11.00 per hundred pounds of milk from March through June 2003 to a high of

$19.30 in May of 2004. On average, milk prices during this time were between

$13.00 and $14.00. In general, milk prices rise during late summer and early fall,

decrease in mid-winter, and remain stable through the summer.

a. Monthly milk prices received by farmers, all milk 1991–2006 (January through

June):

 Milk Prices* 1991–2006 (Dollars)

 Month (January–June)

Year January February March April May June 

1991 11.70 11.60 11.40 11.30 11.30 11.40 

1992 13.40 12.90 12.50 12.60 12.80 13.20 

1993 12.50 12.20 12.20 12.60 12.90 13.00 

1994 13.60 13.40 13.50 13.40 12.80 12.60 

1995 12.60 12.50 12.60 12.30 12.30 12.10 

1996 14.10 13.90 13.80 13.90 14.30 14.80 

1997 13.50 13.40 13.60 13.20 12.70 12.20 

1998 14.70 14.90 14.50 14.00 13.30 14.20 

1999 17.40 15.20 15.20 12.60 12.80 13.10 

2000 12.00 11.80 11.80 11.90 12.00 12.30 

2001 13.00 13.10 13.90 14.60 15.50 16.20 

2002 13.60 13.10 12.60 12.50 12.10 11.50 

2003 11.80 11.30 11.00 11.00 11.00 11.00 

2004 13.20 13.60 15.50 18.10 19.30 18.20 

2005 16.10 15.40 15.50 15.20 14.70 14.40 

2006 14.40 13.50 12.60 12.10 11.90 11.90 

*Per 100 pounds of milk. 
USDA APHIS VS / 19

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

b. Monthly milk prices received by farmers, all milk 1991–2006 (July through

December):

 Milk Prices* 1991–2006 (Dollars)

 Month (July–December)

Year Jul Aug Sep Oct Nov Dec 

1991 11.80 12.40 12.80 13.50 13.90 13.80 

1992 13.40 13.50 13.50 13.40 13.10 12.80 

1993 12.80 12.40 12.80 13.10 13.60 13.50 

1994 12.20 12.40 12.80 13.00 13.10 12.80 

1995 12.00 12.40 12.80 13.40 14.00 13.90 

1996 15.40 15.90 16.50 16.40 15.20 14.30 

1997 12.10 12.70 13.10 14.10 14.70 14.80 

1998 14.30 15.50 16.80 17.80 17.90 18.10 

1999 13.80 15.00 15.70 14.90 14.40 12.20 

2000 12.60 12.50 12.90 12.50 12.50 13.00 

2001 16.20 16.50 17.10 15.60 14.40 13.50 

2002 11.10 11.30 11.60 12.10 11.90 11.90 

2003 12.10 13.30 14.50 15.00 14.40 13.80 

2004 16.10 14.90 15.50 15.60 16.20 16.40 

2005 14.80 14.80 15.30 15.50 15.10 14.80 

2006 11.70 12.00 13.00 13.60 13.90 14.20 

*Per 100 pounds of milk.
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

20 / Dairy 2007

Monthly Milk Prices Received by Farmers, All Milk 1991–2006

$10

$11

$12

$13

$14

$15

$16

$17

$18

$19

$20

'91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06

Year

Dollars per Cwt

c. Annual milk prices received by farmers, all milk 1991–2006:

 Annual Milk Prices1 1991–2006 (Dollars)

 Nominal Dollars2 2000 Dollars3

1991 12.27 14.53 

1992 13.15 15.22 

1993 12.84 14.52 

1994 13.01 14.41 

1995 12.78 13.87 

1996 14.75 15.71 

1997 13.36 14.00 

1998 15.46 16.02 

1999 14.38 14.69 

2000 12.40 12.40 

2001 15.05 14.70 

2002 12.18 11.69 

2003 12.55 11.80 

2004 16.13 14.78 

2005 15.19 13.48 

2006 12.97 11.16 

1

Per 100 pounds of milk. 

2

Prices producers received. 

3

Nominal prices adjusted for inflation. 
USDA APHIS VS / 21

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

6. Milk cow prices

Cow prices were stable from 1991 through 1998, with prices averaging between

$1,000 and $1,200 per cow. Since 1998, cow prices have varied more, with a low

of $1,240 per cow in 1999 and a high of $1,870 in 2005.

Milk-cow prices received by producers, 1991–2006:

 Milk–Cow Prices1 (Dollars)

Year January April July October 

Annual 

Nominal 

Dollars2

2002 

Dollars3

1991 1,100 1,090 1,090 1,100 1,100 1,303 

1992 1,100 1,120 1,150 1,150 1,130 1,308 

1993 1,140 1,160 1,170 1,170 1,160 1,312 

1994 1,170 1,190 1,160 1,160 1,170 1,296 

1995 1,150 1,140 1,130 1,090 1,130 1,227 

1996 1,060 1,070 1,090 1,130 1,090 1,161 

1997 1,090 1,110 1,100 1,090 1,100 1,153 

1998 1,070 1,110 1,120 1,180 1,120 1,161 

1999 1,250 1,240 1,280 1,380 1,280 1,308 

2000 1,330 1,340 1,350 1,350 1,340 1,340 

2001 1,320 1,400 1,590 1,700 1,500 1,465 

2002 1,610 1,710 1,670 1,430 1,600 1,536 

2003 1,380 1,300 1,310 1,380 1,340 1,259 

2004 1,390 1,580 1,720 1,640 1,580 1,444 

2005 1,620 1,770 1,830 1,870 1,770 1,570 

2006 1,840 1,770 1,680 1,650 1,730 1,488 

1

Cows that calved. 

2

Prices producers received. 

3

Nominal prices adjusted for inflation. 
Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

22 / Dairy 2007

7. Dairy cow slaughter

Approximately 2 to 3 million dairy cows have been slaughtered annually since

1991. The number of cows slaughtered as a percentage of January 1 inventory

ranged from 25.0 to 32.2 percent.

Recent changes in dairy-cow slaughter, 1991-2006:

 Dairy-Cow Slaughter 

Year 1,000 Head

Percent of January 1 

Cow Inventory 

Percent 

Previous Year 

1991 2,840.0 28.5 106.3 

1992 2,892.0 29.7 101.8 

1993 2,994.8 31.0 103.6 

1994 2,857.8 30.1 95.4 

1995 2,861.7 30.2 100.1 

1996 3,036.9 32.2 106.1 

1997 2,926.2 31.4 96.4 

1998 2,619.6 28.5 89.5 

1999 2,573.3 28.2 98.2 

2000 2,631.5 28.7 102.3 

2001 2,581.9 28.2 98.1 

2002 2,606.9 28.6 101.0 

2003 2,859.9 31.3 109.7 

2004 2,362.7 26.3 82.6 

2005 2,252.1 25.0 95.3 

2006 2,353.5 26.0 104.5 
USDA APHIS VS / 23

Section I: Historical Changes in the U.S. Dairy Industry—A. General Trends

8. Value of production

In 2006, milk sales accounted for 23.6 percent of the value of selected U.S.

commodities (cattle, milk, poultry, swine, sheep and wool, catfish and trout, and

honey). Since dairy cows, bulls, and steers are also marketed for beef (cattle),

the percentage of value assigned to the entire dairy industry totals more than

one-quarter of the selected U.S. commodity value.

Value of production for selected U.S. commodities, 2002-2006:

 Year 

 2002 2003 2004 2005 2006 

Commodity 

Value

($1,000) Pct. 

Value

($1,000) Pct. 

Value

($1,000) Pct. 

Value

($1,000) Pct. 

Value

($1,000) Pct. 

Cattle 27,097,532 34.7 32,112,931 36.7 34,830,872 33.0 36,628,658 34.4 35,740,774 35.7 

Milk 20,720,482 26.6 21,381,324 24.4 27,567,726 26.1 26,873,946 25.2 23,573,744 23.6 

Poultry1 20,501,173 26.3 23,295,445 26.6 28,857,215 27.4 28,174,715 26.5 26,842,833 26.8 

Swine 8,690,923 11.1 9,663,024 11.0 13,072,025 12.4 13,606,780 12.8 12,703,842 12.7 

Sheep and 

wool 335,635 0.4 419,891 0.5 441,199 0.4 479,397 0.4 392,598 0.4 

Catfish and 

trout2 476,902 0.6 484,894 0.5 546,390 0.5 551,483 0.5 555,675 0.6 

Honey 228,338 0.3 253,106 0.3 196,259 0.2 160,428 0.2 161,314 0.2 

Total 78,050,985 100.0 87,610,615 100.0 105,511,686 100.0 106,475,407 100.0 99,970,780 100.0 

1

Includes boilers, eggs, turkeys, and chickens (value of sales). 

2

Total of sales for trout (excluding eggs), and catfish foodsize, broodfish, stocker, and fingerling sales. 
Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

24 / Dairy 2007

B. Dairy Industry

Changes by State

Note: The following tables describe U.S. dairy industry changes by State

between 1991 and 2007, based on USDA–NASS data. The tables also

identify which States were in the four NAHMS national dairy studies: the

National Dairy Heifer Evaluation Project (NDHEP) 1991, Dairy 1996, Dairy

2002, and Dairy 2007.

1. Milk cow inventory

States in the Western United States have shown the largest growth in the

number of milk cows since 1992. Arizona, California, Colorado, Idaho, Kansas,

Nevada, New Mexico, Oregon, and Utah have all increased cow numbers since

1992. States in the Southeast, including Alabama, Arkansas, Louisiana, and

Mississippi, had the largest percentage decline in dairy cows, but these States

represented less than 5 percent of the overall dairy population. In 2007,

California had the largest number of dairy cows (1.79 million) followed by

Wisconsin (1.245 million), and New York (628,000).
USDA APHIS VS / 25

Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

Changes in U.S. milk cow inventories by State:

Number of Milk Cows that Calved 

(1,000 Head) January 

State 1992 1996 2002 2007 

2007 as 

Percent of 

1992 

2007 as 

Percent of 

1996 

2007 as 

Percent of 

2002 

Alabama 43* 32 20 13 30.2 40.6 65.0 

Alaska 0.8 0.8 1.2 0.6 75.0 75.0 50.0 

Arizona 96 118 140 175 182.3 148.3 125.0 

Arkansas 69 58 33 19 27.5 32.8 57.6 

California 1,160* 1,320* 1,620* 1,790* 154.3 135.6 110.5 

Colorado 77* 82 93* 115 149.4 140.2 123.7 

Connecticut 33* 31 24 19 57.6 61.3 79.2 

Delaware 9 10 9 7 77.8 70.0 77.8 

Florida 179* 155* 152* 130 72.6 83.9 85.5 

Georgia 105* 98 86 75 71.4 76.5 87.2 

Hawaii 10 10 7 3.8 38.0 38.0 54.3 

Idaho 178* 245* 377* 502* 282.0 204.9 133.2 

Illinois 170* 145* 115* 103 60.6 71.0 89.6 

Indiana 145* 140* 154* 166* 114.5 118.6 107.8 

Iowa 270* 245* 205* 210* 77.8 85.7 102.4 

Kansas 95 83 96 110 115.8 132.5 114.6 

Kentucky 185 160* 125* 93* 50.3 58.1 74.4 

Louisiana 79 72 54 30 38.0 41.7 55.6 

Maine 41* 40 38 32 78.0 80.0 84.2 

Maryland 95* 91 81 60 63.2 65.9 74.1 

Massachusetts 31* 27 21 15.5 50.0 57.4 73.8 

Michigan 332* 326* 299* 324* 97.6 99.4 108.4 

Minnesota 660* 585* 500* 455* 68.9 77.8 91.0 

Mississippi 60 53 34 22 36.7 41.5 64.7 

Missouri 210 185* 140* 114* 54.3 61.6 81.4 

Montana 24 20 19 18 75.0 90.0 94.7 

Nebraska 90* 70 68 60 66.7 85.7 88.2 

Nevada 20 23 25 27 135.0 117.4 108.0 

New Hampshire 21* 20 18 14.5 69.0 72.5 80.6 

New Jersey 24 23 13 10.5 43.8 45.7 80.8 

New Mexico 101 195* 290* 360* 356.4 184.6 124.1 

New York 740* 700* 675* 628* 84.9 89.7 93.0 

North Carolina 99* 84 66 48 48.5 57.1 72.7 

North Dakota 80 63 42 31 38.8 49.2 73.8 

Ohio 320* 285* 260* 274* 85.6 96.1 105.4 

Oklahoma 97 94 84 70 72.2 74.5 83.3 

Oregon 100* 95* 105 115 115.0 121.1 109.5 

Pennsylvania 663* 636* 588* 550* 83.0 86.5 93.5 

Rhode Island 2.4* 2.1 1.4 1.1 45.8 52.4 78.6 

South Carolina 33 26 20 17 51.5 65.4 85.0 

South Dakota 132 115 87 81 61.4 70.4 93.1 

Tennessee 165* 120* 90* 67 40.6 55.8 74.4 

Texas 385 400* 315* 347* 90.1 86.8 110.2 

Utah 76 90 93 86 113.2 95.6 92.5 

Vermont 163* 157* 154* 140* 85.9 89.2 90.9 

Virginia 140* 128 120* 100* 71.4 78.1 83.3 

Washington 238* 260* 247* 235* 98.7 90.4 95.1 

West Virginia 23 21 16 13 56.5 61.9 81.3 

Wisconsin 1,650* 1,475* 1,280* 1,245* 75.5 84.4 97.3 

Wyoming 9 6 5 7 77.8 116.7 140.0 

U.S. 9,728.2 9,419.9 9,105.6 9,129 93.8 96.9 100.3 

NAHMS total 7,910.4 7,829 7,799 7,533 95.2 96.2 96.6 

*NAHMS participating States. 
Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

26 / Dairy 2007

2. Number of U.S. dairy operations

With the exception of Alaska, the number of dairy operations in all States has

decreased since 1991. In 2006, Wisconsin had the largest number of dairy

operations (14,900) followed by Pennsylvania (8,700) and New York (6,400).

California reported 2,300 operations, but had the highest number of dairy cows,

demonstrating a large number of cows per herd.

Photo by Dr. Jason Lombard
USDA APHIS VS / 27

Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

a. Changes in number of U.S. dairy operations, by State:

 Number of Operations1 with Milk Cows 

State 19912 19953 20014 20065

2006 as 

Percent 

of 1991 

2006 as 

Percent 

of 1995 

2006 as 

Percent 

of 2001 

Alabama 1,100* 510 250 170 15.5 33.3 68.0 

Alaska 30 30 30 30 100.0 100.0 100.0 

Arizona 500 300 250 200 40.0 66.7 80.0 

Arkansas 2,000 1,700 700 280 14.0 16.5 40.0 

California 4,200* 3,300* 2,500* 2,300* 54.8 69.7 92.0 

Colorado 1,400* 1,000 800* 630 45.0 63.0 78.8 

Connecticut 500* 380 310 220 44.0 57.9 71.0 

Delaware 160 150 110 90 56.3 60.0 81.8 

Florida 1,000* 800* 510* 460 46.0 57.5 90.2 

Georgia 1,400* 1,100 720 580 41.4 52.7 80.6 

Hawaii 80 60 30 30 37.5 50.0 100.0 

Idaho 1,900* 1,500* 1,000* 800* 42.1 53.3 80.0 

Illinois 3,000* 2,600* 1,900* 1,300 43.3 50.0 68.4 

Indiana 4,500* 3,900* 2,900* 2,100* 46.7 53.8 72.4 

Iowa 7,000* 5,200* 3,500* 2,400* 34.3 46.2 68.6 

Kansas 2,300 1,600 1,200 900 39.1 56.3 75.0 

Kentucky 5,500 4,000* 2,900* 2,000* 36.4 50.0 69.0 

Louisiana 1,800 1,100 610 350 19.4 31.8 57.4 

Maine 1,100* 750 600 460 41.8 61.3 76.7 

Maryland 1,600* 1,100 950 810 50.6 73.6 85.3 

Massachusetts 800* 500 350 240 30.0 48.0 68.6 

Michigan 6,000* 4,700* 3,300* 2,700* 45.0 57.4 81.8 

Minnesota 15,000* 12,000* 7,800* 5,400* 36.0 45.0 69.2 

Mississippi 1,300 800 480 330 25.4 41.3 68.8 

Missouri 6,900 5,000* 3,700* 2,600* 37.7 52.0 70.3 

Montana 1,600 900 650 600 37.5 66.7 92.3 

Nebraska 2,700* 1,800 1,100 700 25.9 38.9 63.6 

Nevada 260 200 150 100 38.5 50.0 66.7 

New Hampshire 400* 400 260 200 50.0 50.0 76.9 

New Jersey 450 400 230 150 33.3 37.5 65.2 

New Mexico 1,300 900* 500* 450* 34.6 50.0 90.0 

New York 12,200* 10,000* 7,300* 6,400* 52.5 64.0 87.7 

North Carolina 1,800* 1,300 900 590 32.8 45.4 65.6 

North Dakota 2,100 1,500 850 500 23.8 33.3 58.8 

Ohio 8,900* 6,800* 5,200* 4,400* 49.4 64.7 84.6 

Oklahoma 3,000 2,400 1,700 1,400 46.7 58.3 82.4 

Oregon 1,900* 1,300* 820 720 37.9 55.4 87.8 

Pennsylvania 14,500* 11,800* 10,300* 8,700* 60.0 73.7 84.5 

Rhode Island 60* 40 30 30 50.0 75.0 100.0 

South Carolina 800 350 240 200 25.0 57.1 83.3 

South Dakota 3,300 2,400 1,400 750 22.7 31.3 53.6 

Tennessee 3,500* 2,600* 1,500* 1,100 31.4 42.3 73.3 

Texas 5,300 4,000* 2,100* 1,300* 24.5 32.5 61.9 

Utah 1,500 1,000 760 560 37.3 56.0 73.7 

Vermont 2,600* 2,100* 1,600* 1,200* 46.2 57.1 75.0 

Virginia 2,800* 2,100 1,500* 1,300* 46.4 61.9 86.7 

Washington 3,000* 1,800* 1,000* 790* 26.3 43.9 79.0 

West Virginia 2,000 1,100 600 470 23.5 42.7 78.3 

Wisconsin 33,000* 28,000* 19,100* 14,900* 45.2 53.2 78.0 

Wyoming 600 400 270 250 41.7 62.5 92.6 

U.S. 180,640 139,670 97,460 75,140 41.6 53.8 77.1 

NAHMS total 137,860 112,300 80,910 59,740 43.3 53.2 73.8 

1

An operation is any place having one or more milk cows, excluding cows used to nurse calves, on hand any 

time during the year.

2

NASS, Milk Final Estimates 1988-92. 

3

NASS, Milk Cows and Production Final Estimates 1993-97, January 1999. 

4

NASS, Livestock Operations, Final Estimates 1998-2002, April 2004. 

5

NASS, Farms, Land in Farms, and Livestock Operations, 2006 Summary, February 2007. 

*NAHMS participating States. 
Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

28 / Dairy 2007

Similar to the changes in the number of dairy operations, the number of licensed

dairy operations (Grade A or B) decreased from 2002 to 2006 for every State

except Alaska, which remained the same over the 5-year period. More than four

of five U.S. dairy operations (82.5 percent) were licensed.

b. Changes in U.S. licensed dairy operations by State:

 Number of U.S. Licensed Dairy Operations (Grade A or B)

 Year 

State 2002 2003 2004 2005 2006 

2006 as 

Percent 

of 2002 

2006 as 

Percent of 

NASS 

Operations 

Alabama 120* 110 100 90 75 62.5 44.1 

Alaska 10 10 10 10 10 100.0 33.3 

Arizona 160 160 150 140 130 81.3 65.0 

Arkansas 320 290 240 210 190 59.4 67.9 

California 2,030* 2,060* 2,030* 1,970* 1,960 96.6 85.7 

Colorado 180* 180 170* 170 170 94.4 27.0 

Connecticut 210* 200 180 170 170 81.0 77.3 

Delaware 95 90 90 90 60 63.2 66.7 

Florida 210* 190* 190* 180 160 76.2 34.8 

Georgia 380* 360 330 320 300 78.9 55.2 

Hawaii 10 10 10 5 5 50.0 16.7 

Idaho 815* 775* 755* 725* 690 84.7 86.3 

Illinois 1,340* 1,295* 1,210* 1,155 1,105 82.5 85.0 

Indiana 2,150* 2,010* 1,900* 1,830* 1,750 81.4 83.3 

Iowa 2,760* 2,500* 2,420* 2,370* 2,230 80.8 92.9 

Kansas 565 530 490 460 450 79.6 50.0 

Kentucky 1,835 1,630* 1,435* 1,335* 1,240 67.6 62.0 

Louisiana 380 340 310 280 250 65.8 71.4 

Maine 430* 400 390 370 350 81.4 76.1 

Maryland 735* 715 695 655 630 85.7 77.8 

Massachusetts 250* 230 220 200 190 76.0 79.2 

Michigan 3,040* 2,840* 2,680* 2,590* 2,530 83.2 93.7 

Minnesota 6,775* 6,235* 5,810* 5,530* 5,295 78.2 98.1 

Mississippi 300 270 250 230 190 63.3 57.8 

Missouri 2,110 1,980* 1,840* 1,780* 1,710 81.0 65.8 

Montana 120 110 120 120 110 91.7 18.3 

Nebraska 540* 500 450 405 380 70.4 54.3 

Nevada 35 30 30 30 30 85.7 30.0 

New Hampshire 170* 150 140 140 130 76.5 65.0 

New Jersey 140 130 130 120 120 85.7 80.0 

New Mexico 160 170* 170* 170* 170 106.3 37.8 

New York 6,930* 6,700* 6,600* 6,430* 5,970 86.1 93.3 

North Carolina 420* 395 375 365 345 82.1 58.5 

North Dakota 510 440 400 360 320 62.7 64.0 

Ohio 4,100* 3,960* 3,780* 3,610* 3,530 86.1 80.2 

Oklahoma 440 420 400 380 350 79.5 25.0 

Oregon 350* 350* 350 330 320 91.4 44.4 

Pennsylvania 9,240* 9,130* 8,720* 8,700* 8,610 93.2 99.0 

Rhode Island 20* 20 20 20 15 75.0 50.0 

South Carolina 120 120 110 95 95 79.2 47.5 

South Dakota 860 780 700 650 600 69.8 80.0 

Tennessee 860* 820* 760* 710 650 75.6 59.1 

Texas 890 850* 810* 780* 740 83.1 56.9 

Utah 405 365 360 345 320 79.0 57.1 

Vermont 1,480* 1,390* 1,280* 1,230* 1,170 79.1 97.5 

Virginia 940* 910 850* 815* 775 82.4 59.6 

Washington 660* 640* 620* 610* 610 92.4 77.2 

West Virginia 170 150 140 130 120 70.6 25.5 

Wisconsin 17,300* 16,400* 15,570* 15,100* 14,640 84.6 98.3 

Wyoming 40 35 35 30 30 75.0 12.0 

U.S. 74,110 70,375 66,825 64,540 61,990 83.6 82.5 

NAHMS total 64,435 61,925 59,600 55,575 
USDA APHIS VS / 29

Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

3. U.S. average dairy herd size

Average dairy herd sizes in 2006 ranged from 20 cows in Alaska to 875 in

Arizona. The U.S. average dairy herd size in 2006 was 121.5 cows, more than

double the average in 1991 (53.9 cows).

Changes in U.S. average dairy herd size by State:

Average Herd Size1

 

(Number of Milk Cows) 

State 1991 1995 2001 2006 

2006 as 

Percent 

of 1991 

2006 as 

Percent 

of 1995 

2006 as 

Percent of 

2001 

Alabama 39.1* 62.7 80.0 76.5 195.7 121.9 95.6 

Alaska 26.7 26.7 43.3 20.0 74.9 75.0 46.2 

Arizona 192.0 403.3 588.0 875.0 455.7 216.9 148.8 

Arkansas 34.5 32.9 45.7 67.9 196.8 206.0 148.4 

California 276.2* 408.8* 659.2* 778.3* 281.8 190.4 118.1 

Colorado 55.0* 84.0 125.0* 182.5 331.8 217.3 146.0 

Connecticut 66.0* 78.9 77.4 86.4 130.9 109.4 111.6 

Delaware 56.3 64.7 81.8 77.8 138.2 120.3 95.1 

Florida 179.0* 195.0* 294.1* 282.6 157.9 144.9 96.1 

Georgia 75.0* 88.2 118.1 129.3 172.4 146.6 109.5 

Hawaii 125.0 156.7 220.0 126.7 101.4 80.9 57.6 

Idaho 93.7* 170.7* 388.0* 627.5* 669.7 367.7 161.7 

Illinois 56.7* 53.8* 60.5* 79.2 139.7 147.1 130.9 

Indiana 32.2* 35.9* 52.1* 79.0* 245.3 220.2 151.8 

Iowa 38.6* 46.3* 59.7* 87.5* 226.7 188.8 146.5 

Kansas 41.3 51.3 89.2 122.2 295.9 238.5 137.1 

Kentucky 33.6 38.3* 42.1* 46.5* 138.4 121.6 110.5 

Louisiana 43.9 62.7 78.7 85.7 195.2 136.6 108.9 

Maine 37.3* 54.7 61.7 69.6 186.6 127.3 112.8 

Maryland 59.4* 79.1 85.3 74.1 124.7 93.7 86.9 

Massachusetts 38.8* 54.0 60.0 64.6 166.5 119.6 107.6 

Michigan 55.3* 68.1* 91.2* 120.0* 217.0 176.3 131.6 

Minnesota 44.0* 48.6* 62.4* 84.3* 191.6 173.4 135.0 

Mississippi 46.2 63.8 70.8 66.7 144.4 104.6 94.1 

Missouri 30.4 36.4* 37.0* 43.8* 144.1 120.5 118.4 

Montana 15.0 22.2 27.7 30.0 200.0 135.0 108.3 

Nebraska 33.3* 38.3 60.9 85.7 257.4 223.6 140.7 

Nevada 76.9 125.0 166.7 270.0 351.1 216.0 162.0 

New Hampshire 52.5* 50.0 69.2 72.5 138.1 145.0 104.7 

New Jersey 53.3 55.0 56.5 70.0 131.3 127.3 123.8 

New Mexico 77.7 216.7* 602.0* 800.0* 1029.6 369.2 132.9 

New York 60.7* 70.2* 92.5* 98.1* 161.6 139.8 106.1 

North Carolina 55.0* 63.1 71.1 81.4 148.0 129.0 114.4 

North Dakota 38.1 41.3 47.1 62.0 162.7 150.0 131.8 

Ohio 36.0* 41.3* 50.4* 62.3* 173.1 150.7 123.6 

Oklahoma 32.3 39.2 49.4 50.0 154.8 127.7 101.2 

Oregon 52.6* 71.5* 139.0 159.7 303.6 223.3 114.9 

Pennsylvania 45.7* 53.7* 56.8* 63.2* 138.3 117.7 111.3 

Rhode Island 40.0* 50.0 46.7 36.7 91.8 73.3 78.6 

South Carolina 41.3 74.3 83.3 85.0 205.8 114.4 102.0 

South Dakota 40.0 46.7 61.4 108.0 270.0 231.4 175.8 

Tennessee 47.1* 45.0* 58.7* 60.9 129.3 135.4 103.8 

Texas 72.6 99.3* 151.0* 266.9* 367.6 268.9 176.8 

Utah 50.7 91.0 122.4 153.6 303.0 168.8 125.5 

Vermont 62.7* 74.3* 96.3* 116.7* 186.1 157.1 121.2 

Virginia 50.0* 60.0 79.3* 76.9* 153.8 128.2 97.0 

Washington 79.3* 142.8* 247.0* 297.5* 375.2 208.3 120.4 

West Virginia 11.5 18.2 26.7 27.7 240.9 152.1 103.7 

Wisconsin 50.0* 51.8* 66.5* 83.6* 167.2 161.5 125.6 

Wyoming 15.0 16.5 16.3 28.0 186.7 169.7 171.8 

U.S. 53.9 67.1 93.8 121.5 225.4 181.1 129.6 

NAHMS total 57.4 69.7 96.4 126.1 219.7 181.4 130.4 

1

Average herd size = NASS published number of dairy operations/following-year January 1 milk cow 

inventory. 

*NAHMS participating States. 
Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

30 / Dairy 2007

4. Milk production per cow

Milk production per cow has increased in every State except Alaska since 1991.

In 2006, Colorado had the highest milk production per cow at 23,155 pounds. In

addition, Arizona (22,855), Idaho (22,326), Michigan (22,188), and Washington

(23,055) all had milk production per cow higher than 22,000 pounds during 2006.

The U.S. average milk per cow was 19,951 pounds in 2006, up 32.7 percent

from 15,031 pounds in 1991.

Photo by Judy Rodriguez
USDA APHIS VS / 31

Section I: Historical Changes in the U.S. Dairy Industry—B. Dairy Industry Changes by State

Milk per Cow Production (Pounds) 

State 19911 19952 20013 20064

2006 as 

Percent 

of 1991 

2006 as 

Percent 

of 1995 

2006 as 

Percent 

of 2001 

Alabama 12,707* 14,176 14,286 14,500 114.1 102.3 101.5 

Alaska 13,300 17,000 13,055 12,250 92.1 72.1 93.8 

Arizona 18,032 19,735 22,036 22,855 126.7 115.8 103.7 

Arkansas 11,687 12,150 12,343 13,250 113.4 109.1 107.3 

California 18,534* 19,573* 20,904* 21,815* 117.7 111.5 104.4 

Colorado 17,338* 18,687 21,413* 23,155 133.6 123.9 108.1 

Connecticut 15,848* 16,438 18,240 19,316 121.9 117.5 105.9 

Delaware 14,130 14,500 16,667 17,429 123.3 120.2 104.6 

Florida 13,933* 14,698* 15,758* 16,417 117.8 111.7 104.2 

Georgia 13,523* 15,550 16,663 18,234 134.8 117.3 109.4 

Hawaii 13,056 13,654 14,107 13,256 101.5 97.1 94.0 

Idaho 16,399* 18,147* 21,194* 22,326* 136.1 123.0 105.3 

Illinois 14,936* 15,887* 17,414* 19,204 128.6 120.9 110.3 

Indiana 15,439* 15,375* 16,778* 19,994* 129.5 130.0 119.2 

Iowa 15,095* 16,124* 18,024* 20,146* 133.5 124.9 111.8 

Kansas 12,680 14,390 17,312 20,920 165.0 145.4 120.8 

Kentucky 11,231 12,469* 12,969* 13,276* 118.2 106.5 102.4 

Louisiana 11,675 11,908 11,704 12,375 106.0 103.9 105.7 

Maine 14,786* 16,025 17,211 17,938 121.3 111.9 104.2 

Maryland 14,480* 14,725 15,780 17,078 117.9 116.0 108.2 

Massachusetts 15,000* 16,000 17,000 17,375 115.8 108.6 102.2 

Michigan 15,690* 17,071* 19,373* 22,188* 141.4 130.0 114.5 

Minnesota 14,354* 15,894* 17,278* 18,587* 129.5 116.9 107.6 

Mississippi 12,098 12,909 14,200 14,826 122.5 114.9 104.4 

Missouri 13,451 14,158* 13,441* 16,000* 119.0 113.0 119.0 

Montana 13,750 15,000 18,211 18,632 135.5 124.2 102.3 

Nebraska 13,913* 14,797 16,194 18,328 131.7 123.9 113.2 

Nevada 17,500 18,128 19,412 20,667 118.1 114.0 106.5 

New Hampshire 15,143* 16,300 17,889 19,533 129.0 119.8 109.2 

New Jersey 14,160 13,913 16,643 16,182 114.3 116.3 97.2 

New Mexico 19,561 18,969* 20,750* 21,515* 110.0 113.4 103.7 

New York 15,005* 16,501* 17,530* 18,879* 125.8 114.4 107.7 

North Carolina 15,424* 16,314 17,224 18,510 120.0 113.5 107.5 

North Dakota 12,622 13,094 14,000 14,688 116.4 112.2 104.9 

Ohio 14,446* 15,917* 16,519* 17,737* 122.8 111.4 107.4 

Oklahoma 12,354 13,611 15,407 16,630 134.6 122.2 107.9 

Oregon 16,590* 17,289* 18,074 19,000 114.5 109.9 105.1 

Pennsylvania 15,263* 16,492* 18,112* 19,390* 127.0 117.6 107.1 

Rhode Island 14,333* 14,773 16,571 17,273 120.5 116.9 104.2 

South Carolina 12,273 14,481 17,476 16,353 133.2 112.9 93.6 

South Dakota 12,309 13,398 15,393 18,580 150.9 138.7 120.7 

Tennessee 11,863* 13,740* 14,511* 15,657 132.0 114.0 107.9 

Texas 14,036 15,244* 15,666* 21,328* 152.0 139.9 136.1 

Utah 15,975 16,739 17,211 20,291 127.0 121.2 117.9 

Vermont 14,683* 16,210* 17,444* 18,383* 125.2 113.4 105.4 

Virginia 14,614* 15,116 15,975* 17,363* 118.8 114.9 108.7 

Washington 18,814* 20,091* 22,324* 23,055* 122.5 114.8 103.3 

West Virginia 11,739 12,667 15,563 15,385 131.1 121.5 98.9 

Wisconsin 14,140* 15,397* 17,182* 18,824* 133.1 122.3 109.6 

Wyoming 12,563 13,197 14,000 17,612 140.2 133.5 125.8 

U.S. 15,031 16,405 18,162 19,951 132.7 121.6 109.9 

1

NASS, Milk Final Estimates 1988-92. 

2

NASS, Milk Cows and Production Final Estimates 1993-97, May 1999. 

3

NASS, Milk Cows and Production Final Estimates 1998-2002, May 2004. 

4

NASS, Milk Production, Disposition and Income 2006 Summary, April 2007. 

*NAHMS participating States 

Changes in milk per cow, by State:
Section II: Changes in World Dairy Production—General Trends

32 / Dairy 2007

Section II: Changes in World Dairy Production

Note: Tables in this section are comprised from data collected by USDA’s

Foreign Agricultural Service (FAS).

General Trends

1. Milk cow inventory

In 2006 India had 38 million milk cows, more than any other nation in the world.

China showed the largest increase in number of milk cows from 1991 to 2006

(approximatley 1.5 to 7.9 million, respectively). The former Soviet Union had the

largest decrease in number of milk cows from 1991 to 2006 (approximately 20.6

to 9.9 million, respectively). Total milk cow numbers for these selected countries

decreased 5.9 percent since 1991 but remained steady from 2001 to 2006 at

approximately 125.6 million.

Changes in milk cow inventories in selected countries:

 Number of Milk Cows (1,000 Head) 

Continent/Country 1991 1995 2001 2006 

2006 as 

Percent 

of 1991 

2006 as 

Percent 

of 1995 

2006 as 

Percent 

of 2001 

North 

America Canada 1,410 1,244 1,091 1,019 72.3 81.9 93.4 

 Mexico 6,440 6,440 6,800 6,875 106.8 106.8 101.1 

 United States 9,826 9,466 9,103 9,112 92.7 96.3 100.1 

Subtotal 17,676 17,150 16,994 17,006 96.2 99.2 100.1 

South 

America Argentina 2,000 2,350 2,450 2,150 107.5 91.5 87.8 

 Brazil 15,500 17,500 15,900 15,290 98.6 87.4 96.2 

Subtotal 17,500 19,850 18,350 17,440 99.7 87.9 95.0 

European 

Union1 Subtotal 25,3922

 22,4342 25,7473 24,9444 98.2 111.2 96.9 

Eastern 

Europe Poland 4,707 3,715 3 4 -- -- -- 

 Romania 1,600 1,778 1,564 4 -- -- -- 

Subtotal 6,307 5,493 1,564 4 -- -- -- 

Former 

Soviet 

Union 

Russia 20,557 18,400 12,500 9,900 48.2 53.8 79.2 

 Ukraine 8,378 7,818 4,958 3,491 41.7 44.7 70.4 

Subtotal 28,935 26,218 17,458 13,391 46.3 51.1 76.7 

South Asia India 30,700 33,000 35,900 38,000 123.8 115.2 105.8 

Subtotal 30,700 33,000 35,900 38,000 123.8 115.2 105.8 

Asia China 1,459 2,252 2,848 7,900 541.5 350.8 277.4 

 Japan 1,081 1,034 971 900 83.3 87.0 92.7 

Subtotal 2,540 3,286 3,819 8,800 346.5 267.8 230.4 

Oceania Australia5 1,629 1,786 2,281 1,870 114.8 104.7 82.0 

 New Zealand6 2,723 2,994 3,557 4,100 150.6 136.9 115.3 

Subtotal 4,352 4,780 5,838 5,970 137.2 124.9 102.3 

Total 133,402 132,211 125,670 125,551 94.1 95.0 99.9 

1

Based on deliveries. 

2

EU-15 includes Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, 

Luxembourg, Netherlands, Portugal, Spain, Sweden, U.K. 

3

EU-25 includes Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, 

Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, 

Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, U.K. 

4

EU-27 includes Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, 

France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, 

Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, U.K. 

5

Year ending June 30 of year shown. 

6

Year ending May 31 of year shown. 

Source: FAS Dairy: World Markets and Trade. Based upon counselor and attaché reports, official 

statistics, and results of office research. 
USDA APHIS VS / 33

Section II: Changes in World Dairy Production—General Trends

2. Milk production

The European Union produced the most milk in 2006 at 132.2 million metric

tons, a 7.5 percent increase from 1991. China showed the largest increase in

production with a 687 percent increase from 1991 to 2006, which is not

surprising considering the nation’s large increase in cow numbers. Excluding

China, milk production in 2006 as a percentage of 2001 increased no more than

15.5 percent and decreased no more than 6 percent in any country. Milk

production over all selected countries was approximately 419 million metric tons

in 2006, an increase of about 41 million metric tons since 1991.

Changes in milk production in selected countries:

 Milk Production (1,000 Metric Tons) 

Continent/Country 1991 1995 2001 2006 

2006 as 

Percent 

of 1991 

2006 as 

Percent 

of 1995 

2006 as 

Percent 

of 2001 

North 

America Canada 7,790 7,920 8,106 8,041 103.2 101.5 99.2 

 Mexico 10,200 7,399 9,501 10,051 98.5 135.8 105.8 

United 

States 66,994 70,440 74,994 82,462 123.1 117.1 110.0 

Subtotal 84,984 85,759 92,601 100,554 118.3 117.3 108.6 

South 

America Argentina 6,400 8,500 9,500 10,200 159.4 120.0 107.4 

 Brazil 14,200 18,375 22,300 25,230 177.7 137.3 113.1 

Subtotal 20,600 26,875 31,800 35,430 172.0 131.8 111.4 

European 

Union1 Subtotal 122,9612

 121,7402 130,0693 132,2064 107.5 108.6 101.6 

Eastern 

Europe Poland 14,504 11,420 3 4 -- -- -- 

 Romania 4,391 5,885 5,188 4 -- -- -- 

Subtotal 18,895 17,305 5,188 4 -- -- -- 

Former 

Soviet 

Union 

Russia 51,971 39,300 33,000 31,100 59.8 79.1 94.2 

 Ukraine 22,409 17,181 13,169 13,017 58.1 75.8 98.8 

Subtotal 74,380 56,481 46,169 44,117 59.3 78.1 95.6 

South Asia India 28,200 32,500 36,400 41,000 145.4 126.2 112.6 

Subtotal 28,200 32,500 36,400 41,000 145.4 126.2 112.6 

Asia China 4,646 5,764 10,255 31,934 687.3 554.0 311.4 

 Japan 8,260 8,382 8,300 8,138 98.5 97.1 98.0 

Subtotal 12,906 14,146 18,555 40,072 310.5 283.3 216.0 

Oceania Australia5 6,578 8,433 10,864 10,395 158.0 123.3 95.7 

New 

Zealand6 8,122 9,684 13,162 15,200 187.1 157.0 115.5 

Subtotal 14,700 18,117 24,026 25,595 174.1 141.3 106.5 

Total 377,626 372,923 384,808 418,974 110.9 112.3 108.9 1

Based on deliveries. 

2

EU-15 includes Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, 

Luxembourg, Netherlands, Portugal, Spain, Sweden, U.K. 

3

EU-25 includes Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, 

Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, 

Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, U.K. 

4

EU-27 includes Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, 

France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, 

Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, U.K. 

5

Year ending June 30 of year shown. 

6

Year ending May 31 of year shown. 

Source: FAS Dairy: World Markets and Trade. Based upon counselor and attaché reports, official 

statistics, and results of office research. 
Section III: Management, NAHMS Population Estimates—A. Dairy Herd Information

34 / Dairy 2007

Note: The NDHEP 1991 study included only herds with 30 or more milk

cows; the Dairy 1996, Dairy 2002, and Dairy 2007 studies included

operations with one or more milk cows.

Section III: Management, NAHMS Population Estimates

A. Dairy Herd

Information

1. Record-keeping systems

The percentage of operations using hand-written records decreased from 88.3

percent in 1991 to 73.5 percent in 2007, while the percentage of operations using

on-farm computers increased from 13.7 percent to 19.4 during the same time

period. These changes in record-keeping systems are consistent with the need

to quickly store and access information on larger operations.

a. Percentage of operations by...

...type of recordkeeping systems 

used for the 

dairy operation. 

...type of individual animal record-keeping 

systems used. 

System 

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Handwritten, 

such as a 

ledger or 

notebook 88.3 (1.0) 80.7 (1.0) 74.3 (1.1) 73.5 (1.2) 

Dairy Herd 

Improvement 

Association 57.5 (1.8) 43.4 (1.2) 44.8 (1.3) 45.9 (1.4) 

Computer 

located on 

the operation 13.7 (1.1) 15.1 (0.8) 19.4 (0.9) 19.4 (0.9) 

Computer 

located off 

the operation 11.8 (1.2) 9.9 (0.8) 5.0 (0.5) 4.9 (0.5) 

Other system 11.4 (1.1) 6.0 (0.7) 4.1 (0.5) 4.4 (0.6) 

Any 99.9 (0.1) 100.0 (0.0) 95.2 (0.6) 95.1 (0.7) 
USDA APHIS VS / 35

Section III: Management, NAHMS Population Estimates—A. Dairy Herd Information

For operations using on- or off-farm computer data records systems, the

percentage of operations that used Dairy Comp 305 increased from 19.4

percent in 2002 to 34.9 percent in 2007. The percentage of cows whose records

were kept using Dairy Comp 305 increased from 48.5 percent in 2002 to 60.3

percent in 2007.

b. For operations using on- or off-farm computer record systems, percentage of

operations (and percentage of cows on these operations) by primary

computerized record system used:

Dairy 2002 Dairy 2007 

Operations Cows Operations Cows 

Primary 

Computer 

Record 

System Percent 

Std. 

Error Percent 

Std. 

Error Percent 

Std. 

Error Percent 

Std. 

Error 

Dairy Comp 

305 19.4 (1.7) 48.5 (1.9) 34.9 (2.3) 60.3 (2.0) 

PC Dart 12.5 (1.4) 10.3 (0.8) 19.3 (1.9) 10.2 (0.9) 

DHI Plus 13.3 (1.7) 13.7 (1.3) 15.0 (1.7) 15.9 (1.7) 

Other 54.8 (2.5) 27.5 (1.6) 30.8 (2.4) 13.6 (1.3) 

Total 100.0 100.0 100.0 100.0 
Section III: Management, NAHMS Population Estimates—A. Dairy Herd Information

36 / Dairy 2007

2. Identification

Identification methods for dairy cattle have changed little since 1996. The

percentage of operations using ear tags or electronic identification (ID) increased

slightly, while the percentage of operations using collars or photographs or

sketches showed a slight decrease. These changes are expected, as herd sizes

increase and housing systems change from individual animal stalls to freestalls

and drylot housing.

a. Percentage of operations by type of individual animal ID used on at least

some dairy cows:

Percent Operations 

ID Type 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Ear tags 81.2 (1.1) 85.8 (1.0) 86.5 (1.0) 

Collars 22.3 (1.0) 16.8 (1.0) 12.7 (0.9) 

Photographs or 

sketches 17.4 (1.0) 14.1 (0.9) 13.3 (1.0) 

Branding (all methods) 4.9 (0.5) 4.9 (0.5) 4.4 (0.5) 

Electronic ID 0.3 (0.1) 0.1 (0.1) 4.1 (0.5) 

Tattoos (other than for 

brucellosis) 6.5 (0.6) 8.8 (0.7) 7.7 (0.6) 

Other 10.1 (0.9) 10.8 (0.8) 10.5 (0.9) 

Any 91.2 (0.9) 93.7 (0.8) 93.0 (0.8) 
USDA APHIS VS / 37

Section III: Management, NAHMS Population Estimates—A. Dairy Herd Information

The percentage of operations that used ear tags as herd identification at the

operation level increased from 29.1 percent in 2002 to 34.5 percent in 2007, but

the percentage of cows that had ear tags as herd ID remained unchanged. The

use of electronic ID increased, as only 0.4 percent of cows were equipped with

electronic ID in 2002 as a method to indentify animals as part of a herd

compared with 3.9 percent in 2007.

b. Percentage of operations (and percentage of cows) by type of herd

identification used:

Dairy 2002 Dairy 2007 

Operations Cows Operations Cows 

ID Type Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error 

Ear tags 29.1 (1.1) 41.5 (1.2) 34.5 (1.3) 41.0 (1.5) 

Collars 4.2 (0.5) 3.9 (0.5) 2.8 (0.4) 2.9 (0.5) 

Branding (all 

methods) 3.7 (0.3) 18.0 (1.1) 3.1 (0.3) 18.7 (1.4) 

Electronic ID 0.1 (0.0) 0.4 (0.2) 1.8 (0.3) 3.9 (0.6) 

Tattoos (other 

than for 

brucellosis) 3.4 (0.4) 3.8 (0.5) 2.5 (0.4) 4.6 (0.8) 

Other 2.7 (0.4) 2.9 (0.4) 2.0 (0.4) 1.7 (0.4) 

Any 34.2 (1.1) 53.6 (1.1) 36.4 (1.3) 54.0 (1.5) 
Section III: Management, NAHMS Population Estimates—A. Dairy Herd Information

38 / Dairy 2007

3. Breed of dairy cows

Holsteins remain the predominant breed in the United States, and the percentage

of operations with specific breeds has not changed since 1991.

Percentage of operations by primary breed:

Percent Operations 

Breed 

NDHEP

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Holstein 94.9 (0.7) 93.0 (0.8) 92.4 (0.7) 92.2 (0.7) 

Jersey 2.4 (0.4) 4.1 (0.6) 3.8 (0.5) 3.5 (0.4) 

Ayrshire 0.6 (0.3) 0.3 (0.1) 0.3 (0.1) 0.3 (0.1) 

Brown Swiss 1.0 (0.4) 0.4 (0.2) 0.9 (0.2) 0.9 (0.3) 

Guernsey 0.9 (0.3) 1.7 (0.4) 1.1 (0.3) 0.9 (0.3) 

Other 0.2 (0.2) 0.5 (0.2) 1.5 (0.4) 2.2 (0.5) 

Total 100.0 100.0 100.0 100.0 

4. Cow registration

The percentage of operations with no registered cows increased from 59.6 in

1991 to 71.7 percent in 2007. Operations with 100 percent of cows registered

remained similar from 1991 to 2007.

Percentage of operations by percentage of dairy cows registered with a breed

association:

Percent Operations 

Percent 

Dairy Cows 

Registered 

NDHEP 

1991 

Std. 

Error 

Percent 

Dairy Cows 

Registered 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

0 59.6 (1.7) 0 65.5 (1.2) 71.6 (1.2) 71.7 (1.3) 

1 to 9 10.8 (1.1) 0.1 to 9.9 6.7 (0.6) 5.3 (0.6) 5.6 (0.6) 

10 to 50 16.3 (1.3) 10.0 to 49.9 10.3 (0.7) 8.1 (0.7) 6.5 (0.7) 

51 to 75 3.2 (0.6) 50.0 to 74.9 4.4 (0.6) 3.2 (0.4) 2.1 (0.4) 

76 to 99 4.2 (0.6) 75.0 to 99.9 5.5 (0.6) 4.2 (0.5) 5.2 (0.6) 

100 5.9 (0.7) 100 7.6 (0.7) 7.6 (0.7) 8.9 (0.8) 

Total 100.0 Total 100.0 100.0 100.0 
USDA APHIS VS / 39

Section III: Management, NAHMS Population Estimates—A. Dairy Herd Information

5. Quality assurance programs

The percentage of operations participating in any milk quality assurance program

increased from 40.6 percent in 2002 to 47.3 percent in 2007. Local milkcooperative or processor-sponsored programs showed the largest increase in

the percentage of operation participation from 2002 to 2007 (35.2 to 42.2 percent

of operations, respectively).

Percentage of operations that participated in quality assurance programs, by type

of program:

Percent Operations 

Program Type Dairy 2002 Std. Error Dairy 2007 Std. Error 

State sponsored 7.8 (0.6) 8.8 (0.7) 

Local milk cooperative/ 

processor sponsored 35.2 (1.3) 42.2 (1.4) 

National industry 

sponsored 2.8 (0.4) 3.1 (0.4) 

Other 2.8 (0.4) 2.0 (0.3) 

Any 40.6 (1.3) 47.3 (1.4) 
Section III: Management, NAHMS Population Estimates—B. Productivity

40 / Dairy 2007

B. Productivity 1. Rolling herd average milk production

Rolling herd average (RHA) milk production for all herds and for herds with

primarily Holsteins has increased approximately 4,000 pounds (cow average)

since 1991.

a. Operation average RHA milk production (lb/cow):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

16,703 (96) 16,587 (100) 18,235 (103) 19,175 (112) 

Primarily Holsteins* 

Op. 

Avg.

Std. 

Error

Op. 

Avg.

Std. 

Error

Op. 

Avg.

Std. 

Error

Op. 

Avg.

Std. 

Error

16,925 (96) 16,925 (99) 18,590 (102) 19,482 (115) 

*Operations where Holsteins accounted for 50 percent or more of the January 1, 1998, January 1, 

2002, or January 1, 2007, cow inventory or was the main breed of dairy herd (1991).

b. Cow average RHA milk production (lb/cow):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

17,532 (81) 18,198 (79) 20,210 (80) 21,483 (115) 

Primarily Holsteins*

Cow 

Avg. 

Std. 

Error

Cow 

Avg. 

Std. 

Error

Cow 

Avg. 

Std. 

Error

Cow 

Avg. 

Std. 

Error

17,735 (80) 18,442 (78) 20,467 (79) 21,807 (114) 

*Operations where Holsteins accounted for 50 percent or more of the January 1, 1998, January 1, 

2002, or January 1, 2007, cow inventory or was the main breed of dairy herd (1991).
USDA APHIS VS / 41

Section III: Management, NAHMS Population Estimates—B. Productivity

2. Age at first calving

The age at first calving at the operation level decreased from 25.9 months in

1991 to 25.2 in 2007. Similarly, the cow average age at first calving decreased

from 25.8 to 24.5 months during the same time period.

a. Operation average age at first calving (months):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

25.9 (0.1) 25.8 (0.1) 25.4 (0.1) 25.2 (0.1) 

b. Cow average age at first calving (months):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

25.8 (0.1) 25.5 (0.1) 25.0 (0.1) 24.5 (0.1) 
Section III: Management, NAHMS Population Estimates—B. Productivity

42 / Dairy 2007

3. Days dry

In 2007, the average days dry at the operation level and cow level was 57.8 and

58.5 days, respectively. These averages represent a decrease of about 3 days

since 1991.

a. Operation average days dry:

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

61.1 (0.5) 60.5 (0.3) 60.6 (0.3) 57.8 (0.3) 

b. Cow average days dry:

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

61.5 (0.3) 61.7 (0.4) 61.9 (0.2) 58.5 (0.3) 

4. Calving interval

Although the operation average calving interval decreased slightly from 2002 to

2007 (13.3 and 13.2 months, respectively), the average increased from 12.8

months in 1991 to 13.2 in 2007.

a. Operation average calving interval for cows (months):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

12.8 (0.0) 12.9 (0.0) 13.3 (0.0) 13.2 (0.0) 
USDA APHIS VS / 43

Section III: Management, NAHMS Population Estimates—B. Productivity

b. Cow average calving interval for cows (months):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

Cow 

Avg. 

Std. 

Error 

12.9 (0.0) 13.0 (0.0) 13.4 (0.0) 13.3 (0.0) 

Photo by Dr. Jason Lombard
Section III: Management, NAHMS Population Estimates—C. Heifer Management

44 / Dairy 2007

C. Heifer Management 1. Source of heifers

In 2002 and 2007, the majority of heifers were born and raised on the same

operation, and the majority of operations had heifers that were born and raised

on the operation. A higher percentage of heifers were raised off the operation in

2007 compared to 2002 (11.5 and 7.2 percent, respectively).

Percentage of operations and percentage of dairy heifers*, by source of heifers:

Dairy 2002 Dairy 2007 

Operations Heifers Operations Heifers 

Heifer Source Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error 

Heifers born and raised 

on same operation 98.1 (0.3) 89.5 (1.0) 96.5 (0.4) 87.4 (1.2) 

Heifers born on the 

operation but raised 

off the operation 3.6 (0.4) 7.2 (0.8) 4.7 (0.5) 11.5 (1.2) 

Heifers were born 

off the operation 6.7 (0.7) 3.3 (0.8) 6.6 (0.8) 1.1 (0.2) 

Total 100.0 100.0 

*As a percentage of January 1 heifer inventory 

2. Separation from dam

The practice of separating newborn heifer calves from their dams immediately

after birth doubled from 1991 to 2007 (28.0 and 55.9 percent of operations,

respectively).

Percentage of operations by age at which newborn heifer calves were separated

from their dams:

Percent Operations 

Age (Hours) 

NDHEP 

1991 

Std. 

Error Age (Hours)

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

0 (before 

any nursing) 28.0 (1.7) 

Immediately 

(no nursing) 47.9 (1.3) 52.9 (1.3) 55.9 (1.4) 

Less than 12 39.6 (1.7) 

After nursing, 

but less than 

12 hours 

20.8 (1.0) 22.5 (1.1) 22.2 (1.2) 

12 to 24 22.0 (1.4) 12 to 24 17.4 (1.1) 15.9 (1.0) 14.6 (1.0) 

More than 24 10.4 (1.0) More than 24 13.9 (1.0) 8.7 (0.8) 7.3 (0.8) 

Total 100.0 Total 100.0 100.0 100.0 
USDA APHIS VS / 45

Section III: Management, NAHMS Population Estimates—C. Heifer Management

Photo by Judy Rodriguez

3. Colostrum

In 1991, 1996, and 2002, about 3 of 10 operations allowed heifer calves to get

colostrum during first nursing compared to about 4 of 10 operations in 2007. A

smaller percentage of operations hand-fed colostrum from a bucket or bottle in

2007 compared to operations in 1991, 1996, and 2002.

a. Percentage of operations by method normally used for heifer calves’ first

feeding of colostrum:

Percent Operations 

Method 

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

First nursing 33.7 (1.7) 33.5 (1.2) 30.5 (1.2) 36.3 (1.4) 

Hand-fed 

from bucket 

or bottle 64.0 (1.7) 62.5 (1.2) 64.8 (1.3) 59.2 (1.4) 

Hand-fed 

using 

esophageal 

feeder 2.3 (0.6) 3.6 (0.4) 4.4 (0.5) 4.3 (0.5) 

No 

colostrum 0.0 (0.0) 0.4 (0.2) 0.3 (0.1) 0.2 (0.1) 

Total 100.0 100.0 100.0 100.0 
Section III: Management, NAHMS Population Estimates—C. Heifer Management

46 / Dairy 2007

The percentage of operations that estimated immunoglobulin (Ig) levels in

colostrum or evaluated its quality increased across all herd sizes from 2002 to

2007.

b. For operations that hand-fed colostrum, percentage of operations that

estimated Ig levels of the colostrum or evaluated its quality, by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 2.1 (0.6) 7.6 (1.3) 

Medium (100 to 499) 10.6 (1.5) 19.8 (2.3) 

Large (500 or more) 32.2 (2.8) 45.2 (3.2) 

All operations 5.2 (0.5) 13.0 (1.1) 

A smaller percentage of medium and large operations pooled colostrum from

more than one cow in 2007 than in 2002.

c. For operations that normally hand-fed colostrum, percentage of operations

that pooled colostrum from more than one cow, by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 22.1 (1.4) 16.0 (1.7) 

Medium (100 to 499) 37.4 (2.0) 26.0 (2.4) 

Large (500 or more) 70.6 (2.4) 56.9 (3.1) 

All operations 27.0 (1.1) 21.0 (1.3) 
USDA APHIS VS / 47

Section III: Management, NAHMS Population Estimates—C. Heifer Management

The percentage of operations by storage methods for colostrum was essentially

unchanged between 2002 and 2007, with the largest percentage of operations

not storing colostrum. Approximately 6 of 10 operations did not store colostrum

in 2002 and 2007.

d. For operations that hand-fed colostrum, percentage of operations by primary

method of storing colostrum:

Percent Operations 

Method 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Stored without refrigeration 4.4 (0.6) 3.9 (0.7) 

Stored in refrigerator 7.8 (0.6) 11.1 (0.9) 

Stored in freezer 27.7 (1.1) 28.2 (1.6) 

Other 0.5 (0.2) 0.0 (--) 

Not stored 59.6 (1.3) 56.8 (1.8) 

Total 100.0 100.0 

The percentage of operations that pasteurized colostrum did not change from

2002 to 2007.

e. For operations that hand-fed colostrum, percentage of operations that

pasteurized colostrum, by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 0.4 (0.2) 0.2 (0.2) 

Medium (100 to 499) 0.8 (0.3) 0.9 (0.4) 

Large (500 or more) 3.6 (0.9) 6.4 (1.6) 

All operations 0.6 (0.2) 0.8 (0.2) 
Section III: Management, NAHMS Population Estimates—C. Heifer Management

48 / Dairy 2007

Operations provided calves approximately the same amount of colostrum during

the first 24 hours of life from 1991 to 2007, with approximately one-quarter of

operations feeding 2 quarts or less and about one-third feeding 4 or more quarts.

f. For operations that hand-fed colostrum, percentage of operations by amount of

colostrum normally fed during the first 24 hours:

Percent Operations 

Amount 

(Quarts) 

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

2 or less 25.6 (1.8) 21.4 (1.3) 21.4 (1.4) 23.3 (1.6) 

More than 

2 but less 

than 4 48.2 (2.1) 46.6 (1.6) 47.2 (1.7) 45.8 (1.9) 

4 or more 26.2 (1.9) 32.0 (1.5) 31.4 (1.5) 30.9 (1.7) 

Total 100.0 100.0 100.0 100.0 
USDA APHIS VS / 49

Section III: Management, NAHMS Population Estimates—C. Heifer Management

4. Medicated milk replacer

Approximately 56 percent of operations fed medicated milk replacer in 2002 and

2007.

a. Percentage of operations that fed medicated milk replacer, by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 54.4 (1.6) 55.2 (1.8) 

Medium (100 to 499) 64.1 (1.9) 68.2 (2.1) 

Large (500 or more) 37.7 (2.5) 43.6 (3.1) 

All operations 55.7 (1.3) 57.5 (1.4) 

Photo by Judy Rodriguez
Section III: Management, NAHMS Population Estimates—C. Heifer Management

50 / Dairy 2007

5. Weaning age

The age at weaning for both the operation and heifer averages has remained

relatively steady since 1996.

a. Operation average age of heifers at weaning (weeks):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

Op. 

Avg. 

Std. 

Error 

7.9 (0.1) 8.4 (0.1) 8.0 (0.1) 8.2 (0.1) 

Although the percentage of operations that fed milk replacer remained

unchanged between 2002 and 2007, the percentage of operations that fed each

specific medication listed increased from 2002 to 2007.

b. For operations that fed a medicated milk replacer, percentage of operations by

medication used:

Percent Operations 

Medication Used

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Chlortetracycline (CTC) 7.1 (0.7) 12.1 (1.1) 

Oxytetracycline (OTC) 13.7 (0.8) 21.9 (1.5) 

Oxytetracycline in 

combination with Neomycin 

(OxyNEO) 25.6 (1.2) 49.5 (1.9) 

Decoquinate 12.8 (0.9) 18.8 (1.4) 

Lasalocid 3.2 (0.4) 7.2 (0.9) 

Other 3.6 (0.5) 5.4 (0.9) 
USDA APHIS VS / 51

Section III: Management, NAHMS Population Estimates—C. Heifer Management

b. Heifer average age at weaning (weeks):

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Heifer 

Avg. 

Std. 

Error 

Heifer 

Avg. 

Std. 

Error 

Heifer 

Avg. 

Std. 

Error 

Heifer 

Avg. 

Std. 

Error 

8.2 (0.1) 8.7 (0.1) 8.4 (0.1) 8.6 (0.1) 

Photo by Dr. Jason Lombard
Section III: Management, NAHMS Population Estimates—C. Heifer Management

52 / Dairy 2007

6. Preventive practices

Operation use of specific preventive practices for heifers has remained stable or

increased since 1991. The largest increases in the use of preventive practices

were observed for vitamins A-D-E in feed and selenium in feed.

Percentage of operations by preventive practices normally used for heifers:

Percent Operations 

Preventive 

Practice

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Dewormers 62.2 (2.2) 67.3 (1.3) 69.0 (1.2) 69.4 (1.3) 

Coccidiostats 

in feed 37.8 (2.0) 46.5 (1.2) 44.4 (1.3) 46.5 (1.4) 

Vitamins A-D-E 

injection 11.8 (1.3) 16.3 (1.0) 15.3 (1.0) 10.4 (0.7) 

Vitamins A-D-E in 

feed 57.4 (2.2) 76.9 (1.1) 72.7 (1.2) 74.4 (1.2) 

Selenium 

injection 16.2 (1.8) 12.7 (0.8) 13.3 (0.9) 13.2 (0.9) 

Selenium in feed 50.3 (2.2) 70.8 (1.2) 67.6 (1.3) 69.3 (1.3) 

Ionophores in 

feed (e.g., 

Rumensin®, 

Bovatec®) 40.0 (2.2) 42.2 (1.2) 44.2 (1.3) 45.2 (1.4) 

Probiotics NA 13.1 (0.9) 14.2 (0.9) 20.0 (1.1) 

Anionic salts in 

feed NA NA 20.6 (1.1) 20.9 (1.1) 

Other NA 4.8 (0.6) 3.8 (0.5) 4.6 (0.7) 

Any 91.7 (1.1) 93.6 (0.7) 94.9 (0.6) 94.6 (0.7) 
USDA APHIS VS / 53

Section III: Management, NAHMS Population Estimates—C. Heifer Management
Section III: Management, NAHMS Population Estimates—C. Heifer Management

54 / Dairy 2007

Percent Operations 

Disease

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Bovine viral 

diarrhea (BVD) 58.4 (2.1) 69.7 (1.3) 71.5 (1.2) 73.7 (1.3) 

Infectious bovine 

rhinotracheitis 

(IBR) 60.6 (2.1) 66.1 (1.3) 67.0 (1.3) 70.4 (1.3) 

Parainfluenza 

Type 3 (PI3) 57.6 (2.1) 60.1 (1.3) 60.0 (1.3) 61.0 (1.4) 

Bovine 

respiratory 

syncytial virus 

(BRSV) 44.0 (2.1) 58.7 (1.3) 58.2 (1.3) 64.9 (1.4) 

Haemophilus 

somnus 14.7 (1.4) 37.3 (1.3) 31.4 (1.2) 34.2 (1.3) 

Leptospirosis 56.1 (2.2) 67.0 (1.3) 65.1 (1.3) 67.7 (1.3) 

Salmonella NA 18.9 (1.0) 16.8 (1.0) 21.5 (1.1) 

E. coli mastitis NA 18.1 (0.9) 21.3 (1.0) 24.1 (1.1) 

Clostridia 

(blackleg/ 

malignant edema) 20.7 (1.4) 32.3 (1.1) 32.8 (1.1) 34.6 (1.3) 

Brucellosis 66.8 (1.9) 63.8 (1.3) 51.0 (1.3) 41.6 (1.3) 

Mycobacterium 

avium subspecies 

paratuberculosis 

(Johne’s disease) NA 5.4 (0.6) 4.6 (0.5) 5.0 (0.6) 

Neospora NA NA 3.6 (0.4) 6.3 (0.6) 

Other NA 7.3 (0.6) 6.9 (0.6) 6.8 (0.7) 

Any 91.3 (1.3) 86.4 (1.0) 84.4 (1.1) 83.0 (1.1) 

7. Vaccination practices

The percentage of operations administering any vaccine decreased from 91.3

percent in 1991 to 83.0 percent in 2007. With the exceptions of parainfluenza,

brucellosis, and Johne’s disease vaccines, vaccine use for all other diseases

increased. The percentage of operations that vaccinated heifers against

brucellosis decreased from 63.8 percent in 1996 to 41.6 percent in 2007. This

decease may be due to the fact that many States switched from a mandatory to

a voluntary brucellosis vaccination program from 1996 to 2007. In addition, the

number of States that were certified brucellosis-free increased from 34 in 1996 to

49 in 2007, which may have impacted how many operations vaccinated against

brucellosis.

Percentage of operations that normally vaccinated heifers against the following

diseases:
USDA APHIS VS / 55

Section III: Management, NAHMS Population Estimates—C. Heifer Management
Section III: Management, NAHMS Population Estimates—C. Heifer Management

56 / Dairy 2007

8. Types of BVD vaccine

The majority of operations that administered BVD vaccines to heifers switched

from giving killed vaccines in 1996 (58.4 percent of operations) to modified-live

vaccines in 2007 (62.2 percent of operations).

For operations that gave BVD vaccinations to heifers, percentage of operations

by type of BVD vaccine given:

 Percent Operations 

Type of 

BVD 

Vaccine 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Killed 58.4 (1.5) 50.6 (1.6) 43.1 (1.6) 

Modified 

live 40.7 (1.5) 49.2 (1.6) 62.2 (1.5) 
USDA APHIS VS / 57

Section III: Management, NAHMS Population Estimates—D. Heifer Health

D. Heifer Health 1. Calves born alive

The number of calves born alive as a percentage of cow inventory decreased

from 93.4 percent in 1996 to 86.0 percent in 2007.

Number of calves born and alive*, as a percentage of January 1 cow inventory:

Dairy 1996 Dairy 2002 Dairy 2007 

Pct. Std. Error Pct. Std. Error Pct. Std. Error 

93.4 (0.5) 88.8 (0.5) 86.0 (0.6) 

*In Dairy 2007, included “alive at 48 hours.” 

2. Mortality

The percentages of unweaned and weaned heifer calves that died decreased

from 1996 to 2007. The percentage of unweaned calves that died decreased

from 10.5 percent in 2002 to 7.8 percent in 2007. Weaned heifer calf deaths

increased from 2.2 percent in 1991 to 2.8 percent in 2002 and then decreased to

1.8 percent in 2007.

a. Number of unweaned and weaned heifer deaths, as a percentage of heifers

born alive...

...or moved 

onto the 

operation 

NDHEP 1991 Dairy 1996 Dairy 2002 Dairy 2007 

Heifer 

Type Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error 

Unweaned 8.4 (0.4) 10.8 (0.4) 10.5 (0.3) 7.8 (0.2) 

Weaned 2.2 (0.1) 2.4 (0.1) 2.8 (0.1) 1.8 (0.1) 
Section III: Management, NAHMS Population Estimates—D. Heifer Health

58 / Dairy 2007

Scours/diarrhea accounted for more than 50 percent of unweaned heifer deaths

in each study year since 1991, while respiratory problems accounted for 20 to 25

percent of deaths during the same period.

b. Percentage of unweaned heifer deaths by cause:

Percent Deaths 

Cause 

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Scours/ 

diarrhea 52.2 (2.6) 60.5 (1.2) 62.1 (1.1) 56.5 (1.3) 

Respiratory 

problems 21.3 (1.6) 24.5 (1.0) 21.3 (0.9) 22.5 (0.9) 

Joint or navel 

problems 2.2 (0.7) 1.0 (0.1) 1.7 (0.2) 1.6 (0.3) 

Lameness 

or injury NA 0.6 (0.1) 0.5 (0.1) 1.7 (0.3) 

Trauma 2.4 (0.8) NA NA NA 

Lack of 

coordination/ 

severe 

depression NA 0.4 (0.1) 0.4 (0.1) 0.3 (0.1) 

Poison NA 0.3 (0.1) 0.1 (0.0) 0.0 (0.0) 

Calving 

problems NA NA 4.1 (0.6) 5.3 (0.7) 

Other known 11.7 (1.8) 6.4 (1.1) 2.9 (0.4) 4.3 (0.7) 

Unknown 10.2 (1.4) 6.3 (0.9) 6.9 (0.8) 7.8 (0.9) 

Total 100.0 100.0 100.0 100.0 
USDA APHIS VS / 59

Section III: Management, NAHMS Population Estimates—D. Heifer Health
Section III: Management, NAHMS Population Estimates—D. Heifer Health

60 / Dairy 2007

The percentage of weaned heifer deaths caused by respiratory problems

increased from 34.8 percent of deaths in 1991 to 46.5 percent in 2007. Weaned

heifer deaths caused by lameness or injury increased from 4.0 percent of deaths

in 1996 to 12.8 percent in 2007.

c. Percentage of weaned heifer deaths by cause:

Percent Deaths 

Cause 

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Scours/ 

diarrhea 18.4 (2.6) 14.1 (1.6) 12.3 (1.0) 12.6 (1.0) 

Respiratory 

problems 34.8 (3.5) 44.8 (2.1) 50.4 (1.6) 46.5 (1.7) 

Joint or navel 

problems 1.0 (0.4) 1.2 (0.5) 1.4 (0.3) 1.0 (0.3) 

Lameness 

or injury NA 4.0 (0.5) 6.4 (0.6) 12.8 (1.0) 

Trauma 6.7 (0.9) NA NA NA 

Lack of 

coordination/ 

severe 

depression NA 0.5 (0.1) 0.3 (0.1) 0.7 (0.2) 

Poison NA 1.2 (0.3) 1.1 (0.4) 1.9 (0.9) 

Other known 20.8 (2.0) 15.8 (2.4) 12.1 (1.2) 9.9 (1.0) 

Unknown 18.3 (2.1) 18.4 (1.4) 16.0 (1.1) 14.6 (1.2) 

Total 100.0 100.0 100.0 100.0 
USDA APHIS VS / 61

Section III: Management, NAHMS Population Estimates—D. Heifer Health
Section III: Management, NAHMS Population Estimates—D. Heifer Health

62 / Dairy 2007

3. Carcass disposal

The percentage of operations that used rendering to dispose of dead calves

decreased from 43.8 percent in 2002 to 36.5 percent in 2007, while the

percentage of operations that composted dead calves increased from 10.1 to

24.2 percent during the same period.

Percentage of operations by primary method used to dispose of dead calves:

Percent Operations 

Method of Disposal

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Buried 35.3 (1.3) 32.6 (1.3) 

Burned/incinerated 2.8 (0.4) 2.0 (0.4) 

Rendered 43.8 (1.3) 36.5 (1.3) 

Composted 10.1 (0.8) 24.2 (1.2) 

Landfill 2.4 (0.4) 1.7 (0.3) 

Other 5.6 (0.6) 3.0 (0.5) 

Total 100.0 100.0 
USDA APHIS VS / 63

Section III: Management, NAHMS Population Estimates—E. Cow Management

E. Cow Management 1. Home-raised replacements

The percentage of operations that home-raised more than 40 percent of their

cow inventory increased threefold from 2002 to 2007 (8.2 and 24.2 percent,

respectively).

Percentage of operations by percentage of adult-cow inventory that was homeraised:

Percent Operations 

Percent of Home-Raised 

Replacements 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

0 8.4 (0.8) 10.2 (0.8) 

0.1 to 10.0 3.9 (0.6) 3.5 (0.6) 

10.1 to 20.0 23.2 (1.2) 15.8 (1.1) 

20.1 to 30.0 33.1 (1.3) 23.3 (1.2) 

30.1 to 40.0 23.2 (1.1) 22.8 (1.2) 

40.1 or more 8.2 (0.7) 24.4 (1.3) 

Total 100.0 100.0 

2. Housing

A higher percentage of small and medium operations housed maternity cows

separate from lactating cows in 2007 compared with 1996. For all operations, the

use of separate maternity housing increased from 45.4 percent in 1996 to 60.0

percent in 2007.

Percentage of operations in which maternity housing was separate from housing

used for lactating cows, by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 39.1 (1.3) 43.5 (1.6) 51.5 (1.7) 

Medium (100 to 499) 72.6 (2.1) 81.6 (1.7) 80.8 (1.8) 

Large (500 or more) 94.5 (1.8) 91.9 (1.5) 90.4 (2.0) 

All operations 45.4 (1.2) 53.1 (1.3) 60.0 (1.3) 
Section III: Management, NAHMS Population Estimates—E. Cow Management

64 / Dairy 2007

3. Milking facilities

The percentage of operations that used a parlor as a primary milking facility

increased from 28.8 percent in 1996 to 39.5 percent in 2007, while the

percentage of operations that used a tiestall or stanchion decreased from 69.5 to

60.3 percent during the same period. A larger shift was observed in the

percentage of cows, as 54.9 percent of cows were milked in parlors in 1996

compared with 78.2 percent in 2007.

Percentage of operations (and percentage of cows on these operations) by

primary milking1

 facility used:

 Percent Operations Percent Cows2

Facility 

Type

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Parlor 28.8 (0.9) 37.1 (1.0) 39.5 (1.0) 54.9 (1.0) 70.0 (0.8) 78.2 (0.6) 

Tie stall or 

stanchion 69.5 (0.9) 61.9 (1.0) 60.3 (1.0) 43.9 (1.0) 28.9 (0.8) 21.8 (0.6) 

Other 2.9 (0.5) 1.0 (0.2) 0.2 (0.1) 4.3 (0.7) 1.1 (0.2) 0.0 (0.0) 

1

Dairy 1996 did not ask about primary milking facilities; therefore, the column totals for 1996 are greater than 100 percent. 

2

As a percentage of January 1 cow inventory. 
USDA APHIS VS / 65

Section III: Management, NAHMS Population Estimates—E. Cow Management

Photo by Dr. Jason Lombard
Section III: Management, NAHMS Population Estimates—E. Cow Management

66 / Dairy 2007

4. Nutrition

The percentage of operations that fed a total mixed ration increased for all herd

sizes from 1996 to 2007.

a. Percentage of operations that fed a total mixed ration, by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 28.2 (1.3) 36.6 (1.6) 37.8 (1.6) 

Medium (100 to 499) 68.8 (2.0) 78.3 (1.7) 84.7 (1.7) 

Large (500 or more) 84.1 (3.0) 90.2 (1.7) 94.1 (1.4) 

All operations 35.6 (1.1) 47.0 (1.3) 51.1 (1.3) 

The percentage of operations with an RHA milk production of 16,000 pounds or

more that fed a total mixed ration increased from 1996 to 2002 but was similar

between 2002 and 2007.

b. Percentage of operations that fed a total mixed ration, by RHA milk production:

Percent Operations 

RHA Milk 

Production (Pounds) 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Less than 16,000 28.9 (2.0) 25.4 (2.3) 23.5 (2.4) 

16,000 to 19,999 33.2 (1.7) 45.0 (2.2) 42.7 (2.3) 

20,000 or more 55.4 (2.5) 65.7 (2.1) 70.7 (1.9) 
USDA APHIS VS / 67

Section III: Management, NAHMS Population Estimates—E. Cow Management

The percentages of operations that used forage test results to balance feed

rations were similar for individual herd sizes from 1996 to 2007, although a

higher percentage of all operations tested forage in 2007 than in 1996 (75.5 and

67.8 percent, respectively).

c. Percentage of operations that used forage test results to balance feed rations,

by herd size:

Percent Operations 

Herd Size 

(Number Dairy Cows) 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 64.1 (1.4) 66.1 (1.6) 70.1 (1.7) 

Medium (100 to 499) 84.8 (1.3) 87.1 (1.3) 89.9 (1.4) 

Large (500 or more) 89.2 (2.7) 88.8 (1.8) 90.7 (1.8) 

All operations 67.8 (1.2) 71.2 (1.2) 75.5 (1.2) 

The percentage of operations and percentage of cows on these operations that

relied on pasture during the growing season to provide part of the ration forage

component has increased since 2002.

d. Percentage of operations (and percentage of cows on these operations) that

relied on pasture during the growing season to provide part of the ration forage

component for cows:

Percent Operations Percent Cows 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

47.6 (1.3) 58.9 (1.3) 24.7 (0.8) 33.0 (1.3) 
Section III: Management, NAHMS Population Estimates—E. Cow Management

68 / Dairy 2007

5. Number of bulls

The percentage of operations with bulls has remained stable since 1996.

Approximately half of dairy operations (48.3 percent) did not house bulls in 2007.

Percentage of operations by the number of bulls in the January 1 inventory used

for breeding dairy cows or heifers:

Percent Operations 

Number Bulls 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

0 45.4 (1.3) 45.1 (1.4) 48.3 (1.4) 

1 34.8 (1.3) 31.1 (1.3) 28.5 (1.3) 

2 to 4 16.9 (0.8) 19.1 (1.0) 18.6 (1.0) 

5 or more 2.9 (0.2) 4.7 (0.3) 4.6 (0.3) 

Total 100.0 100.0 100.0 

6. Preventive practices

Since 1996, the use of dewormers, selenium injections, and probiotics increased

while vitamin A-D-E injections decreased. In 2007, 95.3 percent of operations

administered any preventive compared with 91.5 percent in 1996.

Percentage of operations by preventive practices normally used for cows:

Percent Operations 

Preventive 

Practice

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Dewormers 53.4 (1.3) 60.3 (1.3) 63.3 (1.4) 

Vitamins 

A-D-E injection 15.5 (0.9) 17.1 (1.0) 12.9 (0.8) 

Vitamins 

A-D-E in feed 81.4 (1.1) 80.2 (1.1) 80.2 (1.2) 

Selenium injection 8.4* (0.6) 18.0 (1.0) 14.9 (0.9) 

Selenium in feed 72.5* (1.2) 75.7 (1.1) 76.1 (1.2) 

Probiotics 16.7 (0.9) 20.4 (1.0) 26.1 (1.2) 

Anionic salts 

in feed NA 27.0 (1.2) 26.7 (1.2) 

Limited potassium 

in dry cow ration NA 45.0 (1.3) 46.9 (1.4) 

Ionophores in feed NA NA 26.8 (1.1) 

Other 4.4 (0.5) 5.4 (0.6) 3.6 (0.6) 

Any 91.5 (0.8) 96.3 (0.6) 95.3 (0.7) 

*Lactating cows only. 
USDA APHIS VS / 69

Section III: Management, NAHMS Population Estimates—E. Cow Management
Section III: Management, NAHMS Population Estimates—E. Cow Management

70 / Dairy 2007

7. Vaccination practices

The use of Salmonella, E coli, and clostridia vaccines has increased since 1996,

while the use of Haemophilus somnus vaccine decreased. Use of the most

common vaccines (BVD, IBR, PI3, BRSV, and Leptospirosis) has remained

steady since 1996.

Percentage of operations that normally vaccinated cows against the following

diseases:

Percent Operations 

Disease

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Bovine viral 

diarrhea (BVD) 71.4 (1.3) 74.2 (1.2) 75.0 (1.3) 

Infectious bovine 

rhinotracheitis 

(IBR) 69.0 (1.3) 69.3 (1.3) 71.3 (1.3) 

Parainfluenza 

Type 3 (PI3) 62.5 (1.3) 62.2 (1.3) 61.9 (1.4) 

Bovine respiratory 

syncytial virus 

(BRSV) 60.8 (1.3) 61.1 (1.3) 65.0 (1.4) 

Haemophilus 

somnus 38.4 (1.3) 32.4 (1.2) 33.6 (1.3) 

Leptospirosis 70.7 (1.3) 70.1 (1.3) 70.0 (1.3) 

Salmonella 18.8 (1.0) 17.1 (1.0) 23.0 (1.1) 

E. coli mastitis 26.6 (1.1) 31.7 (1.2) 33.5 (1.2) 

Clostridia 21.8 (1.0) 25.0 (1.1) 27.7 (1.2) 

Neospora NA 3.3 (0.4) 5.9 (0.6) 

Other 6.5 (0.6) 7.2 (0.6) 7.4 (0.7) 

Any 81.1 (1.1) 82.8 (1.1) 82.2 (1.1) 
USDA APHIS VS / 71

Section III: Management, NAHMS Population Estimates—E. Cow Management
Section III: Management, NAHMS Population Estimates—E. Cow Management

72 / Dairy 2007

8. Types of BVD vaccine

Although the majority of operations administered killed BVD vaccine to cows, the

percentage of operations that used modified-live vaccine increased from 29.3

percent in 1991 to 48.9 percent in 2007. The use of killed BVD vaccine

decreased slightly during the same period.

a. For operations that gave BVD vaccinations to cows, percentage of operations

by type of BVD vaccine given:

A higher percentage of operations used a combination of Type 1 and Type II

vaccines in 2007 compared to 2002 (60.8 and 39.4 percent, respectively).

Producers are becoming more aware of the type of BVD vaccine they used, as

the percentage of operations that did not know which vaccine was used

decreased from 47.6 percent in 2002 to 27.2 percent in 2007.

b. For operations that gave any BVD vaccinations, percentage of operations by

strain of BVD contained in vaccine administered:

 Percent Operations 

Type of 

BVD 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Killed 65.4 (1.4) 61.9 (1.5) 56.3 (1.6) 

Modified 

live 29.3 (1.3) 36.7 (1.5) 48.9 (1.6) 

 Percent Operations 

BVD Strain

Dairy 

2002 

Standard 

Error 

Dairy 

2007 

Standard 

Error 

Type I only 5.4 (0.6) 4.3 (0.6) 

Type II only 7.6 (0.9) 7.7 (0.8) 

Combination (Type I and 

Type II) 39.4 (1.4) 60.8 (1.5) 

Did not know 47.6 (1.5) 27.2 (1.4) 

Total 100.0 100.0 
USDA APHIS VS / 73

Section III: Management, NAHMS Population Estimates—E. Cow Management

The percentages of operations that gave annual BVD booster injections were

similar in 1996, 2002, and 2007, with about 80 percent of operations giving

booster injections.

c. For operations that gave BVD vaccinations to cows, percentage of operations

that gave annual BVD booster injections:

9. Bovine somatotropin (bST)

With the exception of small operations, the percentage of operations that used

bST and the percentage of cows that received bST increased from 1996 to 2002.

From 2002 to 2007, the percentage of large operations that used bST decreased

from 54.4 percent to 42.7 percent. Overall, the percentage of operations that

used bST remained the same in 2002 and 2007 (15.2 percent for both study

years). The percentage of cows that received bST on medium and large

operations decreased from 24.5 and 34.1 percent, respectively, in 2002 to 17.7

and 22.6 percent, respectively, in 2007. Overall, the percentage of cows that

received bST decreased from 22.3 percent in 2002 to 17.2 percent in 2007.

Percentage of operations (and percentage of cows milked on January 1) that

used bST in cows during the current lactation (at the time of interview), by herd

size:

Dairy 1996 

(All Cows in Inventory 

January 1) 

Dairy 2002 

(Cows Milked 

January 1) 

Dairy 2007 

(Cows Milked 

January 1) 

Herd Size 

(Number Dairy 

Cows) 

Pct. 

Ops. 

Std. 

Error 

Pct. 

Cows 

Std. 

Error 

Pct. 

Ops. 

Std. 

Error 

Pct. 

Cows 

Std. 

Error 

Pct. 

Ops. 

Std. 

Error 

Pct. 

Cows 

Std. 

Error 

Small (fewer 

than 100) 6.5 (0.6) 3.7 (0.4) 8.8 (0.8) 6.2 (0.7) 9.1 (0.9) 6.2 (0.7) 

Medium 

(100 to 499) 21.0 (1.7) 13.2 (1.3) 32.2 (1.9) 24.5 (1.5) 28.8 (2.0) 17.7 (1.4) 

Large (500 or 

more) 38.7 (3.9) 17.9 (2.3) 54.4 (2.6) 34.1 (1.8) 42.7 (2.5) 22.6 (1.5) 

All operations 9.4 (0.6) 10.1 (0.7) 15.2 (0.8) 22.3 (0.8) 15.2 (0.8) 17.2 (0.8) 

Percent Operations 

Dairy 

1996 

Standard

Error 

Dairy 

2002 

Standard 

Error 

Dairy 

2007 

Standard 

Error 

77.4 (1.3) 82.9 (1.2) 80.2 (1.3) 
Section III: Management, NAHMS Population Estimates—F. Cow Health

74 / Dairy 2007

F. Cow Health 1. Abortions

Abortion percentage for cows and heifers combined increased from 3.5 percent

in 1996 to 4.5 percent in 2007.

a. Percentage of heifers, cows, and heifers and cows combined that aborted:

Percent Heifers/Cows 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Heifers NA NA 3.31 (0.2) 

Cows NA NA 5.02 (0.2) 

Both heifers and cows 3.5 (0.1) 4.0 (0.1) 4.53 (0.2) 

1

Breeding age or older heifers on January 1, 2007 

2

Cow inventory minus breeding age and older heifers on January 1, 2007 

3

Cow inventory on January 1, 2007. 

The percentages of operations by abortion percentage were similar across study

years.

b. Percentage of operations by reported abortion percentage:

Percent Operations 

Abortion Percent

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Less than 2.0 42.7 (1.3) 39.3 (1.3) 38.2 (1.4) 

2.0 to 4.9 36.2 (1.2) 34.6 (1.2) 34.3 (1.3) 

5.0 to 9.9 16.2 (0.9) 20.3 (1.1) 20.6 (1.1) 

10.0 to 14.9 3.2 (0.5) 4.7 (0.7) 4.9 (0.6) 

15.0 or more 1.7 (0.4) 1.1 (0.3) 2.0 (0.4) 

Total 100.0 100.0 100.0 
USDA APHIS VS / 75

Section III: Management, NAHMS Population Estimates—F. Cow Health

2. Cow morbidity

The percentage of cows with clinical mastitis, lameness, respiratory problems,

infertility problems, or displaced abomasum increased from 1996 to 2007. The

percentage of cows with diarrhea for more than 48 hours or milk fever decreased

from 1996 to 2007.

Percentage of cows by health problem:

Percent Cows* 

Dairy 1996 Dairy 2002 Dairy 2007 

Problem Pct. 

Std. 

Error Pct. 

Std. 

Error Pct. 

Std. 

Error 

Clinical mastitis 13.4 (0.3) 14.7 (0.3) 16.5 (0.5) 

Lameness 10.5 (0.3) 11.6 (0.3) 14.0 (0.4) 

Respiratory 

problems 2.5 (0.1) 2.7 (0.1) 3.3 (0.1) 

Retained placenta 

(more than 24 

hours) 7.8 (0.2) 7.8 (0.2) 7.8 (0.2) 

Infertility problems 

(not pregnant 150 

days after calving) 11.6 (0.3) 11.9 (0.3) 12.9 (0.3) 

Other reproductive 

problems (e.g., 

dystocia, metritis) NA 3.7 (0.2) 4.6 (0.3) 

Diarrhea for more 

than 48 hours 3.4 (0.2) 2.8 (0.2) 2.5 (0.2) 

Milk fever 5.9 (0.1) 5.2 (0.1) 4.9 (0.1) 

Displaced 

abomasum 2.8 (0.1) 3.5 (0.1) 3.5 (0.1) 

Neurological 

problems NA 0.3 (0.0) 0.3 (0.0) 

Other health-related 

problems 2.2 (0.2) 0.8 (0.1) 0.6 (0.1) 

*As a percentage of January 1 respective-year cow inventory. 
Section III: Management, NAHMS Population Estimates—F. Cow Health

76 / Dairy 2007
USDA APHIS VS / 77

Section III: Management, NAHMS Population Estimates—F. Cow Health

3. Permanently removed cows

The percentage of cows removed from medium operations increased from 21.6

percent in 1996 to 23.7 percent in 2007, while the percentage of cows removed

from large operations decreased from 27.4 percent in 1996 to 23.4 percent in

2007. For all operations, there were no differences in the percentages of cows

permanently removed from operations.

a. Percentage of cows permanently removed* as a percentage of January 1

inventory, by herd size:

Percent Cows 

Herd Size 

(Number Dairy Cows) 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 23.9 (0.7) 24.9 (0.6) 24.1 (0.6) 

Medium (100 to 499) 21.6 (0.4) 23.9 (0.5) 23.7 (0.5) 

Large (500 or more) 27.4 (0.8) 27.5 (0.6) 23.4 (0.7) 

All operations 24.0 (0.4) 25.5 (0.3) 23.6 (0.4) 

*Permanently removed cows include those that permanently left the herd but excludes those that 

died. 

There were no changes in the destination of permanently removed cows from

1996 to 2007, with about 75 percent of cows being sent to market, auction, or

stockyard in all three study years.

b. For operations that permanently removed* cows, percentage of permanently

removed cows by destination:

Percent Cows 

Destination

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Sent directly to 

another dairy 4.5 (1.0) 5.7 (0.6) 5.5 (0.7) 

Sent to market, 

auction, or 

stockyard 74.0 (1.4) 74.0 (1.1) 76.2 (1.1) 

Sent directly to 

packer or 

slaughter plant 21.0 (1.2) 19.6 (1.0) 17.5 (1.3) 

Sent elsewhere 0.5 (0.1) 0.7 (0.1) 0.8 (0.3) 

Total 100.0 100.0 100.0 

*Permanently removed cows include those that permanently left the herd but excludes those that 

died. 
Section III: Management, NAHMS Population Estimates—F. Cow Health

78 / Dairy 2007

The reasons cows were permanently removed remained fairly constant from

1996 to 2007, although a lower percentage of cows were removed due to poor

production in 2007 (16.1 percent) than in 1996 (21.4 percent).

c. For operations that permanently removed cows, percentage of cows removed,

by reason:

4. Mortality

The percentage of cows that died increased across herd sizes from 1996 to

2007. The overall percentage of cows that died increased from 3.8 percent in

1996 to 5.7 percent in 2007.

 Percent Removals 

Reason

Dairy 

1996 

Standard 

Error 

Dairy 

2002 

Standard 

Error 

Dairy 

2007 

Standard 

Error 

Udder or mastitis 

problems 25.3 (0.6) 25.4 (0.5) 23.0 (0.6) 

Lameness 

or injury 14.4 (0.6) 15.5 (0.4) 16.0 (0.4) 

Reproductive 

problems 25.5 (0.8) 25.0 (0.5) 26.3 (0.7) 

Poor production 

not related 

to above 21.4 (0.8) 18.3 (0.7) 16.1 (0.7) 

Aggressiveness 

or belligerence 1.0 (0.1) 0.9 (0.1) 0.7 (0.1) 

Other diseases 4.1 (0.5) 5.6 (0.2) 3.7 (0.2) 

Sold as 

replacements to 

another dairy 4.4 (1.0) 5.5 (0.6) 5.8 (0.7) 

Other 3.9 (0.3) 3.8 (0.4) 8.4 (1.1) 

Total 100.0 100.0 100.0 
USDA APHIS VS / 79

Section III: Management, NAHMS Population Estimates—F. Cow Health

Percent Cows 

Herd Size 

(Number Dairy Cows) 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Small (fewer than 100) 3.6 (0.1) 4.4 (0.1) 4.8 (0.1) 

Medium (100 to 499) 3.9 (0.1) 5.0 (0.1) 5.8 (0.2) 

Large (500 or more) 4.0 (0.2) 4.9 (0.1) 6.1 (0.2) 

All operations 3.8 (0.1) 4.8 (0.1) 5.7 (0.1) 

The percentage of cow deaths due to lameness or injury increased from 12.7

percent in 1996 to 20.0 percent in 2007. Conversely, the percentage of cow

deaths due to calving problems and other known reasons decreased from 1996

to 2007.

b. Percentage of cow deaths by cause:

Percent Deaths 

Cause 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Scours, diarrhea, 

or other digestive 

problems 9.0 (1.0) 8.6 (0.5) 10.4 (0.5) 

Respiratory 

problems 9.6 (0.7) 10.3 (0.5) 11.3 (0.7) 

Poison 0.9 (0.2) 0.4 (0.1) 0.4 (0.1) 

Put down due to 

lameness or injury 12.7 (0.7) 13.9 (0.6) 20.0 (0.8) 

Lack of 

coordination or 

severe depression 1.4 (0.2) 1.4 (0.2) 1.0 (0.1) 

Mastitis 16.3 (0.8) 17.1 (0.6) 16.5 (0.7) 

Calving problems 18.3 (0.7) 17.4 (0.7) 15.2 (0.7) 

Other known 

reasons 17.0 (0.9) 11.1 (0.6) 10.2 (0.8) 

Unknown reasons 14.8 (0.8) 19.8 (0.9) 15.0 (1.1) 

Total 100.0 100.0 100.0 

a. Percentage of cows that died as a percentage of January 1 inventory, by herd

size:
Section III: Management, NAHMS Population Estimates—F. Cow Health

80 / Dairy 2007

5. Carcass disposal

Although rendering remained the primary method of dead-cow disposal, the

percentage of operations that used this method decreased from 62.4 percent in

2002 to 56.9 percent in 2007. Conversely, use of composting increased from 6.9

percent of operations in 2002 to 16.8 percent in 2007. These changes in deadcow disposal are similar to those observed in disposing of dead calves,

Percentage of operations by primary method used to dispose of dead cows:

Percent Operations 

Method of Disposal

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Buried 22.7 (1.1) 20.3 (1.1) 

Burned/incinerated 2.2 (0.4) 1.8 (0.4) 

Rendered 62.4 (1.2) 56.9 (1.3) 

Composted 6.9 (0.7) 16.8 (1.0) 

Landfill 1.9 (0.3) 1.7 (0.3) 

Other 3.9 (0.5) 2.5 (0.4) 

Total 100.0 100.0 
USDA APHIS VS / 81

Section III: Management, NAHMS Population Estimates—G. Biosecurity

G. Biosecurity 1. Physical contact with unweaned calves

The percentage of unweaned calves not exposed to weaned calves, bred

heifers, or adult cattle increased from 1996 to 2007.

Percentage of operations where, after separation from the dam, unweaned

heifers did not have physical contact* with the following groups:

Percent Operations 

Age Group

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Weaned calves 

less than 

approximately 4 

months of age 68.5 (2.0) 

Calves from 

approximately 4 

months of age 

to breeding 89.6 (1.3) 

67.0 (1.3) 77.2 (1.2) 76.0 (1.2) 

Bred heifers 

not yet calved 95.4 (0.9) 81.2 (1.1) 86.7 (0.9) 86.8 (1.0) 

Adult cattle 89.8 (1.3) 79.8 (1.1) 84.6 (1.0) 84.3 (1.1) 

*Physical contact = possible nose-to-nose contact or sniffling/touching/licking each other, including through a 

fence. 
Section III: Management, NAHMS Population Estimates—G. Biosecurity

82 / Dairy 2007

2. Physical contact with other animals

The percentage of operations in which pigs, sheep, or beef cattle had physical

contact with dairy cattle and/or their feed, minerals, or water supply was lower in

2007 than in 1991. Dairy-cattle contact with the other listed animals was

unchanged between 1991 and 2007.

Percentage of operations in which the following animals had physical contact

with dairy cattle and/or their feed, minerals, or water supply:

Percent Operations 

Animal Type

NDHEP 

1991 

Std. 

Error 

Dairy 

1996 

Std. 

Error 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Chickens/other 

poultry 10.6 (1.4) 7.5 (0.8) 6.8 (0.7) 8.3 (0.8) 

Horses or other 

equids1

 15.0 (1.6) 11.6 (0.9) 12.8 (0.9) 13.3 (1.0) 

Pigs 5.5 (1.0) 3.9 (0.6) 2.3 (0.4) 2.0 (0.4) 

Sheep 3.0 (0.6) 2.3 (0.5) 1.3 (0.3) 0.9 (0.3) 

Goats 3.1 (0.7) 3.0 (0.5) 2.8 (0.5) 2.5 (0.4) 

Beef cattle 17.3 (1.7) 18.5 (1.1) 10.5 (0.8) 11.3 (1.0) 

Exotic species NA 0.8 (0.2) 0.6 (0.2) 0.7 (0.2) 

Deer or other 

cervidae2

 56.1 (2.2) 49.3 (1.1) 53.1 (1.3) 49.3 (1.4) 

Dogs NA 77.8 (1.1) 70.6 (1.2) 68.9 (1.3) 

Cats NA 90.2 (0.8) 87.8 (0.8) 85.2 (0.9) 

1

In 1991, “horses” was the animal type; “other equids” was not listed. 

2

In 1991, “deer” was the animal type; “other cervidae” was not listed. 
USDA APHIS VS / 83

Section III: Management, NAHMS Population Estimates—G. Biosecurity
Section III: Management, NAHMS Population Estimates—G. Biosecurity

84 / Dairy 2007

3. Biosecurity for new arrivals

From 1996 to 2007, about 4 of 10 operations brought cattle onto the operation.

Percentage of operations that brought the following classes of cattle onto the

operation:

4. Quarantine

There were no differences in the percentages of operations that quarantined new

arrivals between 1996 and 2007 or in the number of days that new additions

were quarantined.

Percent Operations 

Cattle Class

Dairy 

1996 

Std. 

Error Cattle Class 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Calves not 

yet weaned 5.0 (0.7) 

Calves not 

yet weaned 5.1 (0.7) 3.4 (0.6) 

Heifers 

weaned but 

not yet bred 7.3 (0.7) 

Heifers 

weaned but 

not yet bred 6.7 (0.7) 6.4 (0.7) 

Bred heifers 

not yet 

calved 18.5 (0.9) 

Bred heifers 

not yet calved 15.8 (0.9) 12.2 (0.9) 

Lactating 

cows 19.9 (1.0) 

Lactating 

cows 16.4 (1.0) 13.8 (1.0) 

Dry cows 7.1 (0.8) Dry cows 5.9 (0.6) 4.3 (0.6) 

Dairy bulls 13.7 (0.9) 12.5 (0.9) Bulls 8.7 (0.7) 

Beef bulls 2.3 (0.4) 1.7 (0.3) 

 1.9 (0.4) 

Beef heifers 

and cows 1.5 (0.3) 1.3 (0.3) 

Other cattle 

 2.0 (0.3) Steers 1.1 (0.3) 1.8 (0.4) 

Any cattle 43.9 (1.3) Any cattle 45.7 (1.4) 38.9 (1.4) 
USDA APHIS VS / 85

Section III: Management, NAHMS Population Estimates—G. Biosecurity

a. For operations that brought the following classes of cattle onto the operation,

percentage of operations that quarantined the following cattle classes upon

arrival*:

Percent Operations 

Cattle Class

Dairy 

1996 

Std. 

Error Cattle Class 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Calves not yet 

weaned 26.9 (5.2) 

Calves not yet 

weaned 37.0 (7.3) 44.2 (8.3) 

Heifers weaned 

but not yet bred 24.9 (4.7) 

Heifers 

weaned but 

not yet bred 23.9 (3.9) 23.0 (4.7) 

Bred heifers 

not yet calved 16.0 (2.0) 

Bred heifers 

not yet calved 19.6 (2.3) 14.5 (2.3) 

Lactating cows 6.2 (1.7) Lactating cows 9.5 (1.6) 12.1 (2.4) 

Dry cows 17.9 (4.8) Dry cows 7.1 (2.2) 15.9 (4.8) 

Dairy bulls 15.9 (2.4) 17.1 (2.9) Bulls 11.2 (2.4) 

Beef bulls 23.6 (6.5) 20.3 (6.5) 

Other 

heifers/cows 15.7 (6.0) Beef heifers 

and cows 24.0 (8.5) 30.1 (9.8) 

Steers 21.0 (6.6) Steers 40.0 (11.4) 30.0 (9.6) 

*Producers were asked for the number of head brought on and number of head quarantined. 

b. For operations that quarantined new arrivals, average number of days new

arrivals were quarantined, by cattle class:

Average Number of Days 

Cattle Class

Dairy 

1996 

Std. 

Error Cattle Class 

Dairy 

2002 

Std. 

Error 

Dairy 

2007 

Std. 

Error 

Calves not yet 

weaned 40.8 (5.7) 

Calves not yet 

weaned 49.2 (9.3) 42.4 (4.8) 

Heifers weaned 

but not yet bred 21.5 (4.2) 

Heifers 

weaned but 

not yet bred 28.2 (6.0) 20.0 (3.6) 

Bred heifers 

not yet calved 16.8 (2.3) 

Bred heifers 

not yet calved 23.7 (4.0) 22.0 (3.1) 

Lactating cows 11.7 (2.3) Lactating cows 20.1 (4.1) 15.6 (2.5) 

Dry cows 8.9 (2.1) Dry cows 21.4 (4.3) 16.5 (4.3) 

Dairy bulls 19.0 (2.5) 25.3 (3.5) Bulls 21.0 (3.1) 

Beef bulls 32.0 (12.9) 31.9 (12.6) 

Other 

heifers/cows 24.3 (9.1) 

Beef heifers 

and cows 31.1 (6.6) 33.3 (12.1) 

Steers 41.5 (22.0) Steers 41.3 (14.0) 40.7 (18.7) 
Section III: Management, NAHMS Population Estimates—G. Biosecurity

86 / Dairy 2007

5. Vaccine requirements

No changes occurred from 1996 to 2007 in the percentage of operations that

vaccinated new additions for BVD, IBR, and leptospirosis before the cattle were

brought onto the operation. Approximately one-third to one-half of operations

vaccinated for the diseases mentioned above. The percentages of operations

that vaccinated for brucellosis decreased for each herd size from 1996 to 2007.

Since many different ages of cattle are brought onto operations, the lower

brucellosis vaccination percentages may be due partially to cattle too old or

already vaccinated for brucellosis at the time of purchase. Neospora vaccination

has remained unchanged in purchased cattle since 2002. The percentages of

operations vaccinating for any disease decreased for small, large, and all

operations.

For operations that brought any dairy cattle onto the operation, percentage of

operations that normally required vaccination against the following diseases

before bringing animals onto the operation, by herd size:

Percent Operations 

Herd Size (Number Dairy Cows) 

Small 

(Fewer than 100) 

Medium 

(100-499) 

Large 

(500 or More) All Operations 

Disease 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Brucellosis 48.9 

(2.5) 

33.4 

(2.5) 

28.0 

(2.6) 

63.6 

(2.9) 

51.3 

(2.7) 

50.2 

(3.5) 

85.2 

(3.0) 

60.0 

(3.1) 

52.2 

(3.9) 

52.9 

(2.0) 

39.9 

(1.9) 

35.6 

(2.0) 

Bovine viral 

diarrhea (BVD) 

43.1 

(2.4) 

36.2 

(2.5) 

34.8 

(2.8) 

59.4 

(2.9) 

51.2 

(2.7) 

59.9 

(3.4) 

58.8 

(4.8) 

53.9 

(3.2) 

56.7 

(3.7) 

46.8 

(2.0) 

41.3 

(1.9) 

42.9 

(2.1) 

Infectious 

bovine 

rhinotracheitis 

(IBR) 

39.2 

(2.3) 

35.8 

(2.6) 

34.2 

(2.8) 

57.9 

(2.9) 

50.5 

(2.7) 

57.3 

(3.4) 

57.4 

(4.8) 

51.2 

(3.2) 

57.1 

(3.7) 

43.4 

(1.9) 

40.8 

(1.9) 

41.9 

(2.1) 

Leptospirosis 41.9 

(2.4) 

32.5 

(2.5) 

32.0 

(2.7) 

57.7 

(2.9) 

48.5 

(2.7) 

53.6 

(3.4) 

54.3 

(4.8) 

47.5 

(3.2) 

48.4 

(3.8) 

45.4 

(2.0) 

37.8 

(1.8) 

38.8 

(2.1) 

Neospora NA 11.1 

(1.6) 

10.8 

(1.7) NA 15.5 (1.8) 

26.6 

(3.1) NA 16.1 (2.3) 

22.4 

(3.3) NA 12.6 (1.2) 

15.7 

(1.5) 

Other 8.2 

(1.1) 

4.3 

(0.8) 

4.2 

(1.1) 

12.8 

(2.2) 

8.4 

(1.4) 

8.7 

(1.8) 

16.5 

(3.6) 

7.7 

(1.5) 

6.5 

(1.6) 

9.4 

(1.0) 

5.6 

(0.7) 

5.5 

(0.9) 

Any 58.0 

(2.5) 

44.6 

(2.7) 

37.7 

(2.9) 

74.8 

(2.6) 

64.0 

(2.7) 

65.2 

(3.3) 

88.8 

(2.9) 

71.9 

(3.0) 

68.5 

(3.2) 

62.3 

(2.0) 

51.6 

(2.0) 

47.2 

(2.2) 
USDA APHIS VS / 87

Section III: Management, NAHMS Population Estimates—G. Biosecurity
Section III: Management, NAHMS Population Estimates—G. Biosecurity

88 / Dairy 2007

6. Testing requirements

Brucellosis testing for new additions decreased across herd sizes between 1996

and 2007. Tuberculosis testing has also decreased for small, large, and all

operations since 1996. Testing for Mycobacterium avium subspecies

paratuberculosis and BVD remained unchanged from 1996 to 2007. The

percentage of operations that performed any testing decreased for small, large,

and all operations since 1996, with less than 1 in 4 operations that purchased

new additions (23.3 percent) performing any testing during 2007.

a. For operations that brought any dairy cattle onto the operation, percentage of

operations that tested individual animals brought onto the operation, by testing

normally required and by herd size:

Percent Operations 

Herd Size (Number Dairy Cows) 

Small 

(Fewer than 100) 

Medium 

(100-499) 

Large 

(500 or More) All Operations 

Test Type 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Dairy 

1996 

Dairy 

2002 

Dairy 

2007 

Brucellosis 28.5 

(2.1) 

13.1 

(1.8) 

11.6 

(1.9) 

38.3 

(2.9) 

19.5 

(2.1) 

19.8 

(2.8) 

50.6 

(4.4) 

29.9 

(2.7) 

19.0 

(3.0) 

31.0 

(1.7) 

15.9 

(1.3) 

14.3 

(1.5) 

Mycobacterium avium 

subspecies 

paratuberculosis (Johne’s 

disease) 

8.5 

(1.3) 

8.3 

(1.4) 

9.9 

(1.8) 

11.0 

(2.3) 

12.7 

(1.9) 

16.6 

(2.7) 

9.6 

(2.9) 

12.2 

(1.9) 

7.2 

(1.8) 

9.1 

(1.1) 

9.8 

(1.1) 

11.4 

(1.4) 

Bovine viral 

diarrhea (BVD) 

15.1 

(1.6) 

8.6 

(1.4) 

10.7 

(1.8) 

18.4 

(2.5) 

15.6 

(2.1) 

19.4 

(2.8) 

19.4 

(3.9) 

15.0 

(2.1) 

15.8 

(2.7) 

15.9 

(1.3) 

10.9 

(1.1) 

13.3 

(1.4) 

Bovine 

tuberculosis 

(TB) 

22.3 

(1.9) 

10.8 

(1.5) 

12.0 

(1.8) 

26.8 

(2.7) 

14.3 

(1.7) 

17.8 

(2.7) 

31.4 

(4.2) 

20.7 

(2.3) 

15.8 

(2.3) 

23.4 

(1.6) 

12.4 

(1.1) 

13.8 

(1.4) 

Contagious 

mastitis 

pathogens NA NA 

10.5 

(1.8) NA NA 

13.1 

(2.3) NA NA 

16.3 

(3.3) NA NA 

11.7 

(1.4) 

Other 2.3 

(0.5) 

2.8 

(0.8) 

1.6 

(0.6) 

3.6 

(1.4) 

4.3 

(1.3) 

2.2 

(1.0) 

3.9 

(2.1) 

3.5 

(1.1) 

0.4 

(0.2) 

2.6 

(0.5) 

3.2 

(0.6) 

1.7 

(0.5) 

Any 31.3 

(2.1) 

21.2 

(2.2) 

20.2 

(2.4) 

40.0 

(2.9) 

29.4 

(2.5) 

28.2 

(3.2) 

54.3 

(4.5) 

38.8 

(2.9) 

34.7 

(3.8) 

33.7 

(1.8) 

24.5 

(1.6) 

23.3 

(1.8) 
USDA APHIS VS / 89

Section III: Management, NAHMS Population Estimates—G. Biosecurity
Section III: Management, NAHMS Population Estimates—G. Biosecurity

90 / Dairy 2007

A higher percentage of operations in 2007 (13.0 percent) required a bulk-tank

milk culture before bringing animals onto the operation than did operations in

1996 (5.8 percent). While the percentage of all operations that required proof of

bulk-tank somatic cell count was unchanged from 1996 to 2007, the percentage

of large operations that required a count decreased from 45.7 percent in 1996 to

19.8 percent in 2007.

b. For operations that brought any dairy cows onto the farm, percentage of

operations that normally required testing or proof of udder health before bringing

animals onto the farm, by herd size:

Percent Operations 

Herd Size (Number Dairy Cows) 

Small 

(Fewer than 100) 

Medium 

(100-499) 

Large 

(500 or More) All Operations 

Type of 

Proof 1996 2002 2007 1996 2002 2007 1996 2002 2007 1996 2002 2007 

Individual-cow 

milk somatic 

cell count 

24.7 

(2.7) 

26.7 

(3.7) NA 

30.1 

(4.1) 

26.7 

(4.0) NA 

27.9 

(8.7) 

29.5 

(5.2) NA 

25.7 

(2.3) 

26.8 

(2.8) NA 

Bulk-tank milk 

somatic cell 

count 

13.4 

(2.0) 

14.3 

(2.9) 

18.8 

(2.4) 

21.3 

(3.1) 

19.2 

(3.4) 

24.4 

(3.1) 

45.7 

(9.0) 

34.1 

(5.9) 

19.8 

(2.9) 

15.3 

(1.7) 

16.6 

(2.2) 

20.3 

(1.8) 

Individual-cow 

milk culture 

9.1 

(1.7) 

10.7 

(2.5) NA 

8.4 

(1.8) 

10.6 

(2.6) NA 

9.4 

(4.1) 

18.8 

(4.8) NA 

9.0 

(1.4) 

11.0 

(1.8) NA 

Bulk-tank milk 

culture 

3.9 

(0.9) 

9.5 

(2.4) 

10.1 

(1.7) 

11.8 

(2.4) 

10.0 

(2.6) 

17.8 

(2.8) 

35.7 

(8.4) 

31.0 

(6.0) 

20.9 

(2.9) 

5.8 

(0.9) 

10.6 

(1.8) 

13.0 

(1.4) 
USDA APHIS VS / 91

Appendix I: Methodology Overview

Appendix I: Methodology Overview

NAHMS Dairy Studies 

1991 1996 2002 2007 

Data collection dates 

4/1991-

7/1992 

1/1-1/26 

1996 

12/31/2001-

2/12/2002 

1/1-1/31 

2007 

Minimum number 

of dairy cattle 30 1 1 1 

Number of States 28 20 21 17 

Data collectors National Agricultural Statistics Service enumerators 

States as a percentage of U.S. population coverage 

Operations 76.3 80.4 83.0 79.5 

Cows 81.3 83.1 85.7 82.5 

Respondent Sample profile (herd size) 

Small (fewer than 100 cows) 931 1,480 1,131 1,028 

Medium (100-499 cows) 705 873 820 691 

Large (500 or more cows) 175 189 510 475 

Response category 

Survey complete 1,811 2,542 2,461 2,194 

Percent of total 54.1 56.3 63.5 61.7 

No milk cows 646 227 214 

Out of business/ 

no milk sold in 1995 179 183 111 

Out of scope 16 45 6 

Refused 969 821 785 

Did not contact NA 2 126 

Inaccessible 

NA 

164 137 118 

Total 3346 4,516 3,876 3,554 
Appendix II: Study Objectives and Related Outputs

92 / Dairy 2007

Appendix II: Study Objectives and Related Outputs

1. Describe trends in dairy cattle health and management practices

• Part II: Changes in the U.S. Dairy Cattle Industry 1991-2007, February

2008

• Part V: Changes in Dairy Cattle Health and Management in the United States,

1991-2007, expected summer 2008

2. Evaluate management factors related to cow comfort and removal rates

• Dairy Facilities and Cow Comfort on U.S Dairy Operations, 2007 interpretive

report, expected spring 2008

• Info sheets, expected spring 2008

3. Describe dairy calf health and nutrition from birth to weaning and evaluate

heifer disease prevention practices

• Part I: Reference of Dairy Cattle Health and Management Practices in the

United States, 2007, October 2007

• Off-Site Heifer Raising info sheet, November 2007

• Colostrum Management info sheet, February 2008

• Part IV: Reference of Dairy Cattle Health and Management Practices in the

United States, 2007, expected spring 2008

• Calf Health and Management Practices on U.S. Dairy Operations, 2007

interpretive report, expected spring 2008

• Additional info sheets, expected spring 2008

4. Estimate the prevalence of herds infected with bovine viral diarrhea virus

(BVD)

• Info sheets, expected spring 2008.

5. Describe current milking procedures and estimate the prevalence of

contagious mastitis pathogens

• Part III: Reference of Dairy Cattle Health and Management Practices in the

United States, 2007, expected spring 2008.

• Info sheets, expected spring 2008.

6. Estimate the herd-level prevalence and associated costs of Mycobacterium

avium subspecies paratuberculosis

• Info sheets, expected spring 2008.

7. Describe current biosecurity practices and determine producer motivation for

implementing or not implementing biosecurity practices

• Part I: Reference of Dairy Cattle Health and Management Practices in the

United States, 2007, October 2007

• Part III: Reference of Dairy Cattle Health and Management Practices in the

United States, 2007, expected spring 2008