# Presentation: 181179

## Heterosis and Breed Differences for Yield and Somatic Cell Scores of US Dairy Cattle in the 1990’s.

**PAUL VANRADEN**
**Animal Improvement Programs Laboratory**
**Agricultural Research Service, USDA, Beltsville, MD**
- _[paul@aipl.arsusda.](mailto:paul@aipl.arsusda.gov)__[gov](mailto:paul@aipl.arsusda.gov)_

**Notes:**
TITLE SLIDE

## From 1939-1954, M.H. Fohrman studied 113 Guernsey, Jersey, Holstein, and Red Danes crosses at Beltsville.
Another study of 137 Ayrshire, Brown Swiss and Holstein crosses was conducted from 1959-1968 (McDowell and McDaniel, 1968).

**Another study of 137 Ayrshire, Brown Swiss and Holstein crosses was conducted from 1959-1968 (McDowell and McDaniel, 1968).**

*USDA Yearbook of Agriculture 1947*

**Holstein ******** Guernsey**

**Notes:**
Breeds were:
	HOLSTEIN
	JERSEY
	GUERNSEY (female only – no proven GUE SIRE available)
	RED DANE 
Cows milked 3x, barn fed.

## Crossbreds averaged 12,904 pounds of milk and 588 pounds of butterfat, outperforming dams by more than sire proof predictions (Fohrman,1947).
In 1945, advanced register Holsteins averaged 13,833 pounds of milk and 493 pounds of fat. 

**In 1945, advanced register Holsteins averaged ****13,833**** pounds of milk and ****493**** pounds of fat. **

*USDA Yearbook of Agriculture 1947*

**Red Dane ******** Jersey**

**Notes:**
5760kg milk
263kg fat

## Breeds Are Evaluated Separately

**Separate data sets reduce bias in evaluations within breeds, but provide:**
**No evaluations for crossbreds**
**No method to compare cows across breeds**
**New Zealand, Australia, and the Netherlands include crossbreds and account for heterosis in evaluations.**
**USDA-DHIA evaluations exclude crossbred cows unless identified as part of a “grading-up” program.**

## Objectives

**Document the number and type of crossbred cows in the US.**
**Estimate heterosis and breed differences using cows of different breed composition competing in the same herd.**
**Compare the economic merit of crossbred and purebred cows.**

## Traits Considered

**Milk, fat, and protein yields**
**Somatic cell score (SCS)**
**Productive life (PL)**
**Linear type composites not available**
**Body size estimates obtained from literature**
**Udder and leg trait estimates assumed zero **
**Net merit, cheese merit, fluid merit calculated**
**Adjusted to Holstein scale**
**Fertility, mortality, and calving ease not available**

## Yield Traits & SCS Data

**Data were from the national test-day database available May, 2001.**
**572**** herds each with at least 5 crossbred cows**
**10,442**** crossbred cows born since 1990**
**140,421**** purebred herdmates (80% were Holstein)**
**Crossbreds defined by sire breed and maternal grandparent breeds.**
**Sires were purebred, dam breed used for unknown maternal grandparent breed**
**XX (crossbred) not accepted for maternal grandparents**
**Holstein and Red & White considered one breed**

**Notes:**
Because XB’s are not routinely evaluated, pedigree reported less often/completely 
May leads to under-count of XB’s
Started with 12,565 XB in ~3,300 herds 
Restricting data to herds with >= 5 XB cows retained more than 80% of XB’s but reduced herds by more than 80% greatly reducing computing time.

## Yield Traits & SCS Edits

**85% of tests included fat, 82% protein, and          73% SCS**
**Edits applied:**
**Lactation length at least 250 days**
**At least 5 milk tests required before day 305**
**Sire PTA was obtained to account for possible differences in selection intensity of purebreds vs. crossbreds.**

##   Yield Traits & SCS Models

**The models included effects of:**
**Herd-year-season**
**Age**
**Stage of lactation**
**Regression on sire PTA**
**Interaction of sire breed and maternal grand-parent breeds**
**Individual 3-breed interactions were weighted by number of observations to obtain:**
**Specific and general heterosis**
**General recombination effect**

## Number of F1 & Purebred Cows In Mixed Breed Contemporary Groups

|  |  |  |  | Sire Breed |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |
| Dam Breed |  | Ayrshire |  | Brown Swiss | Guernsey | Jersey | Milking Shorthorn | Holstein |
| Ayrshire |  | 933 |  | — | 1 | 26 | 2 | 477 |
| Brown Swiss |  | — |  | 2537 | 8 | 22 | 5 | 242 |
| Guernsey |  | 8 |  | 31 | 1763 | 23 | 4 | 1228 |
| Jersey |  | 18 |  | 22 | 11 | 6593 | 8 | 507 |
| M. Shorthorn |  | — |  | 11 | 1 | — | 1509 | 175 |
| Holstein |  | 145 |  | 819 | 130 | 1631 | 162 | 71,836 |

## Number of F1 & Backcross Cows With Holstein Sire or Grandparent

|  |  | Holstein Genes |  |  |
| --- | --- | --- | --- | --- |
| Second Breed |  |   25% |   50% |   75% |
| Ayrshire |  |   17 |   622 | 124 |
| Brown Swiss |  | 124 | 1061 | 196 |
| Guernsey |  |   32 | 1358 | 367 |
| Jersey |  | 171 | 2138 | 321 |
| M. Shorthorn |  |   14 |   337 |   48 |

## Productive Life Data

**Data from the national database available July, 1994**
**41,131 crossbred cows born from 1960 through 1991**
**726,344 purebred cows in the same herd-years**
**Breed composition from five generation pedigrees**
**Percent genes from each breed**
**Progeny breed = mean of parents’ breeds**
**Unknown parent breed = progeny breed**
**Breed ‘XX’ progeny with unknown parents excluded **
**Holstein and Red & White considered one breed  **

## Productive Life Models

**Model 1 included effects of:**
**Herd-year-season**
**Regressions on breed composition**
**Regression on coefficient of heterosis**
**Incomplete records weighted by age **
**Model 2 also included:**
**Interaction of birth year with breed composition**
**Interaction of birth year with heterosis**

## Results

**Estimated breed means**
**Estimates of heterosis**
**Economic comparisons**
**Rank other breeds on Holstein base**
**Some new crossbreeding theory**

## Breed Effects for Yield TraitsCalculated from Holstein Means

| Breed |  | Milk
(kg/d) | Fat
(kg/d) | Protein
(kg/d) |
| --- | --- | --- | --- | --- |
| Ayrshire |  | 26.3 | 0.99 | 0.81 |
| Brown Swiss |  | 26.8 | 1.04 | 0.87 |
| Guernsey |  | 24.1 | 1.01 | 0.77 |
| Jersey |  | 23.9 | 1.04 | 0.81 |
| M. Shorthorn |  | 25.6 | 0.92 | 0.73 |
| Holstein |  | 31.5 | 1.12 | 0.93 |

**Notes:**
Calculated means for purebred herdmates, based on estimated difference from Holstein means

## Holstein  Jersey

**Holstein ******** Jersey**

| Cow # | Pounds of Milk | % Butterfat | Pounds of Butterfat |
| --- | --- | --- | --- |
|  X-5 | 13,032 | 4.62 | 602 |
| X-11 | 12,584 | 4.82 | 606 |
| X-20 | 12,383 | 5.13 | 636 |
| X-30 | 11,867 | 5.60 | 664 |
| X-38 | 11,929 | 5.09 | 607 |
| X-40 | 13,690 | 4.74 | 649 |
| X-51 | 13,800 | 4.44 | 613 |

**All cows sired by Beltsville Holstein No. 966 **

**Notes:**
Results From Fohrman et. al
HOLSTEIN SIRE PROOF:
	644lbs daus>dam milk (18,416 vs 17,772)
	26lbs daus>dam fat (645 vs 619) 
	#DAUS=31
AVG:	12755lbs milk (3670kg)	
	4.92% fat
	625lbs fat (150kg)

## Jersey  Holstein

**Jersey ******** Holstein**

| Cow # | Pounds of Milk | % Butterfat | Pounds of Butterfat |
| --- | --- | --- | --- |
|  X-1 |   9,784 | 4.85 | 475 |
|  X-3 | 13,065 | 4.71 | 615 |
| X-17 | 13,837 | 3.85 | 533 |
| X-32 | 13,728 | 3.94 | 540 |
| X-41 | 12,453 | 4.63 | 576 |
| X-42 |   9,417 | 4.90 | 461 |
| X-47 | 12,189 | 5.13 | 625 |

**X-1 and X-47 were sired by an unidentified Jersey  sire.  All others sired by Beltsville Jersey No. 1114 **

**Notes:**
AVG:	13054lbs milk (5760kg) 
	4.57% fat
	546lbs protein (260kg)

## Heterosis for Yield Traits Percent of Parent Breed Average

|  |  | Milk |  |  | Fat |  | Protein |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Breed |  |  | Holstein Sire | Holstein Dam | Holstein Sire | Holstein Dam | Holstein Sire | Holstein Dam |
| Ayrshire  |  | 2.4 |  | -2.0 | 2.7 | -1.8 | 2.9 | -2.4 |
| Brown Swiss  |  | 5.6 |  |   3.2 | 4.8 |   4.5 | 4.7 |   3.8 |
| Guernsey  |  | 5.2 |  |   2.4 | 7.1 |   4.4 | 5.5 |   4.0 |
| Jersey  |  | 7.5 |  |   1.6 | 6.6 |   4.5 | 7.2 |   4.1 |
| M. Shorthorn  |  | 2.8 |  |   0.3 | 3.2 |   1.3 | 3.6 |   1.2 |
| Heterosis |  | 3.4 (SE=0.3) |  |  | 4.4 (SE=0.4) |  | 4.1 (SE=0.4) |  |

## Breed Effects & Heterosis for SCS 

| Breed |  | Mean SCS | % Heterosis for Holstein  |
| --- | --- | --- | --- |
| Ayrshire |  2.72 |  |  3.98 |
| Brown Swiss |  2.82 |  | -0.20 |
| Guernsey |  2.86 |  | -0.57 |
| Jersey |  2.99 |  |  2.09 |
| M. Shorthorn |  2.84 |  | -1.52 |
| Holstein |  2.95 |  | — |
| Heterosis  0.72 % (unfavorable) (SE=0.9) |  |  |  |

## Breed Effects & Heterosis for PL 

| Breed |  | PL (mo)
1990 births | 1995 Base Change (mo) | PL (mo) 
1995 births |
| --- | --- | --- | --- | --- |
| Ayrshire | 22.7 |  | .5 | 23.2 |
| Brown Swiss | 23.5 |  | .3 | 23.8 |
| Guernsey | 17.7 |  | .5 | 18.2 |
| Jersey | 24.9 |  | .9 | 25.8 |
| M. Shorthorn | 18.9 |  | .6 | 19.5 |
| Holstein | 23.8 |  | .5 | 24.3 |
| Heterosis  1.2% (SE=0.1) |  |  |  |  |

## Breed Effects & Heterosis for Body Size & Size Composite 

| Breed |  | Mature Size (kg) | Size Composite (BV) |
| --- | --- | --- | --- |
| Ayrshire | 550 |  | -12 |
| Brown Swiss | 680 |  |  -4 |
| Guernsey | 520 |  | -12 |
| Jersey | 450 |  | -21 |
| M. Shorthorn | 590 |  |  -8 |
| Holstein | 680 |  |   0 |
| Heterosis  3.0 % (Lopez-Villalobos, 1998) |  |  |  |

## Breed Differences & Heterosis for Economic Merit  

| Breed |  | Net Merit ($) | Cheese Merit ($) | Fluid Merit ($) |
| --- | --- | --- | --- | --- |
| Ayrshire | -510 |  | -469 |  -728 |
| Brown Swiss | -355 |  | -256 |  -808 |
| Guernsey | -761 |  | -692 | -1117 |
| Jersey | -305 |  | -186 |  -865 |
| M. Shorthorn | -892 |  | -862 | -1073 |
| Holstein | — |  | — | — |
| Heterosis | $197 |  | $207 | $163 |

## Merit of F1 Holstein Crossbreds

| Second Breed |  | Net 
Merit ($) | Cheese
Merit ($) | Fluid
Merit ($) |
| --- | --- | --- | --- | --- |
| Ayrshire |  -58 |  |  -27 | -201 |
| Brown Swiss |   18 |  |   79 | -241 |
| Guernsey | -184 |  | -138 | -395 |
| Jersey |   44 |  |  113 | -269 |
| M. Shorthorn | -249 |  | -223 | -373 |

**Compared to 2000 genetic base for Holstein**

## Mates for Holstein Cows

|  | Brown Swiss |  | Jersey |
| --- | --- | --- | --- |
| Top US Sire | Ransom |  | Fan Club |
| NM$ (breed scale) |   $519 |  |   $467 |
| Breed Difference (from HOL) | - $178 |  | - $153 |
| Heterosis (NM$) |   + $197 |  | + $197 |
| Adjusted NM$ (HOL scale) |   $538 |  |    $511 |
| NM$ Rank (HOL scale) |  28 |  |  40 |
| CM$ Rank (HOL scale) |  13 |  |  12 |

**Notes:**
Cheese Merit Calculations:
			Ransom	Fan CLub
CM$ (breed)	 533		 509
breed difference	-128		 -94
heterosis		+207		+207
adjusted CM$	$612		$622

## Crossbreeding Theory Holstein  Brown Swiss Protein Yield

**Crossbreeding Theory**** Holstein ******** Brown Swiss Protein Yield**

**Notes:**
Recombination effect was positive in this study.
Effects shown are weighted average of reciprocal cross types; possible maternal effects are ignored. 

## Heterosis and Inbreeding

**Animals become more related within but not across breeds.**
**Inbreeding rises by ****2**** to ****3%**** per decade.**
**Crossbreeding removes accumulated inbreeding depression.**
**Heterosis for yield should increase by ****0.6**** to ****0.9%**** per decade.**

## Conclusions

**Conclusions**

## Conclusions

**Currently**** < 0.5%**** of DHI cows are crossbred.**
**Heterosis was about ****4%**** for yield traits, ****< 1%**** (unfavorable) for SCS, and ****1%**** for PL.**
**Profit from Jersey ******** Holstein and Brown Swiss ******** Holstein crosses is higher than from Holsteins.**
**Fewer extreme bulls are found in minor breeds.**
**Backcross yields were higher than expected.**

## Butterfat yield of three breed crosses was greater than from their F1 crossbred dams.
Three breed crosses averaged 14,927 pounds of milk and 641 pounds of butterfat as 2-year-olds in 1947. 

**Three breed crosses averaged ****14,927**** pounds of milk and ****641**** pounds of butterfat as 2-year-olds in 1947. **

*USDA Yearbook of Agriculture 1947*

**Three-Breed Crosses**

**Notes:**
6660kg milk
290kg fat

No predictions based on f1 daus:dam so don’t know whether this can be attributed to ‘hybrid vigor’
This group was heavy on the Red Dane sire
These were 3 breed crosses, so more hybrid vigor should be maintained (~85% in 3 breed rotations), 
as opposed to rotating only 2 breeds (~65% in 2 breed rotations)