# Presentation: 381946

## AIPL Report:  We’re from the government and we’re here to help you!

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## Trend in days open

**Lactation**

## Cow fertility trends

| Year bred | Calving to 1st
breeding (d) |  |  | 70-d NRR for
1st service (%) |  |  | 1st service
CR (%) |  |  | Services per
lactation (no.) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |
| 1996 | 89 | 82 |  |  |  |  |  |  |  |  |  |
| 1997 | 91 | 84 |  |  |  |  |  |  |  |  |  |
| 1998 | 91 | 85 |  |  |  |  |  |  |  |  |  |
| 1999 | 92 | 85 |  |  |  |  |  |  |  |  |  |
| 2000 | 90 | 84 |  |  |  |  |  |  |  |  |  |
| 2001 | 92 | 85 |  |  |  |  |  |  |  |  |  |
| 2002 | 88 | 81 |  |  |  |  |  |  |  |  |  |
| 2003 | 88 | 83 |  |  |  |  |  |  |  |  |  |
| 2004 | 86 | 84 |  |  |  |  |  |  |  |  |  |
| 2005 | 86 | 84 |  |  |  |  |  |  |  |  |  |
| 2006 | 85 | 83 |  |  |  |  |  |  |  |  |  |

## Cow fertility trends

| Year bred | Calving to 1st
breeding (d) |  |  | 70-d NRR for
1st service (%) |  |  | 1st service
CR (%) |  |  | Services per
lactation (no.) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |
| 1996 | 89 | 82 |  | 54 | 57 |  |  |  |  |  |  |
| 1997 | 91 | 84 |  | 55 | 57 |  |  |  |  |  |  |
| 1998 | 91 | 85 |  | 54 | 56 |  |  |  |  |  |  |
| 1999 | 92 | 85 |  | 53 | 55 |  |  |  |  |  |  |
| 2000 | 90 | 84 |  | 53 | 55 |  |  |  |  |  |  |
| 2001 | 92 | 85 |  | 52 | 56 |  |  |  |  |  |  |
| 2002 | 88 | 81 |  | 50 | 53 |  |  |  |  |  |  |
| 2003 | 88 | 83 |  | 48 | 53 |  |  |  |  |  |  |
| 2004 | 86 | 84 |  | 48 | 53 |  |  |  |  |  |  |
| 2005 | 86 | 84 |  | 46 | 52 |  |  |  |  |  |  |
| 2006 | 85 | 83 |  | ... | ... |  |  |  |  |  |  |

## Cow fertility trends

| Year bred | Calving to 1st
breeding (d) |  |  | 70-d NRR for
1st service (%) |  |  | 1st service
CR (%) |  |  | Services per
lactation (no.) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |
| 1996 | 89 | 82 |  | 54 | 57 |  | 36 | 39 |  |  |  |
| 1997 | 91 | 84 |  | 55 | 57 |  | 34 | 37 |  |  |  |
| 1998 | 91 | 85 |  | 54 | 56 |  | 32 | 36 |  |  |  |
| 1999 | 92 | 85 |  | 53 | 55 |  | 31 | 35 |  |  |  |
| 2000 | 90 | 84 |  | 53 | 55 |  | 31 | 35 |  |  |  |
| 2001 | 92 | 85 |  | 52 | 56 |  | 31 | 36 |  |  |  |
| 2002 | 88 | 81 |  | 50 | 53 |  | 29 | 35 |  |  |  |
| 2003 | 88 | 83 |  | 48 | 53 |  | 30 | 36 |  |  |  |
| 2004 | 86 | 84 |  | 48 | 53 |  | 31 | 36 |  |  |  |
| 2005 | 86 | 84 |  | 46 | 52 |  | 30 | 35 |  |  |  |
| 2006 | 85 | 83 |  | ... | ... |  | ... | ... |  |  |  |

## Cow fertility trends

| Year bred | Calving to 1st
breeding (d) |  |  | 70-d NRR for
1st service (%) |  |  | 1st service
CR (%) |  |  | Services per
lactation (no.) |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |  | Holstein | Jersey |
| 1996 | 89 | 82 |  | 54 | 57 |  | 36 | 39 |  | 2.1 | 2.0 |
| 1997 | 91 | 84 |  | 55 | 57 |  | 34 | 37 |  | 2.1 | 2.1 |
| 1998 | 91 | 85 |  | 54 | 56 |  | 32 | 36 |  | 2.2 | 2.1 |
| 1999 | 92 | 85 |  | 53 | 55 |  | 31 | 35 |  | 2.3 | 2.1 |
| 2000 | 90 | 84 |  | 53 | 55 |  | 31 | 35 |  | 2.3 | 2.1 |
| 2001 | 92 | 85 |  | 52 | 56 |  | 31 | 36 |  | 2.3 | 2.1 |
| 2002 | 88 | 81 |  | 50 | 53 |  | 29 | 35 |  | 2.5 | 2.2 |
| 2003 | 88 | 83 |  | 48 | 53 |  | 30 | 36 |  | 2.5 | 2.3 |
| 2004 | 86 | 84 |  | 48 | 53 |  | 31 | 36 |  | 2.5 | 2.3 |
| 2005 | 86 | 84 |  | 46 | 52 |  | 30 | 35 |  | 2.6 | 2.4 |
| 2006 | 85 | 83 |  | ... | ... |  | ... | ... |  | ... | ... |

## Holstein NRR (2005 breedings)

| Parity | 70-day NRR (%) |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
|  | 1st service | 2nd
service | 3rd service | 4th
service | 5th service |
| 1 | 48 | 46 | 43 | 41 | 39 |
| 2 | 45 | 43 | 41 | 40 | 38 |
| 3 | 45 | 44 | 42 | 41 | 39 |
| 4 | 45 | 44 | 43 | 41 | 39 |
| 5 | 45 | 43 | 42 | 41 | 40 |
| >5 | 45 | 43 | 43 | 41 | 39 |

## Holstein CR (2005 breedings)

| Parity | CR (%) |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
|  | 1st service | 2nd
service | 3rd service | 4th
service | 5th service |
| 1 | 32 | 33 | 31 | 29 | 26 |
| 2 | 29 | 30 | 29 | 28 | 26 |
| 3 | 29 | 30 | 30 | 28 | 26 |
| 4 | 28 | 30 | 29 | 27 | 26 |
| 5 | 27 | 28 | 28 | 26 | 25 |
| >5 | 25 | 26 | 26 | 25 | 25 |

## Herds with synchronized breeding

| Synchroni-zation
status | Calving
to 1st breeding
(d) | 70-day
NRR for
1st service
(%) | CR
(%) | Services
per
lactation
(no.) | Preg-nancy rate
(%) |
| --- | --- | --- | --- | --- | --- |
| None | 90 | 46 | 30 | 2.6 | 20.2 |
| Possible | 78 | 40 | 27 | 2.9 | 21.8 |
| Probable | 74 | 38 | 27 | 2.9 | 22.4 |
| Synchronized | 72 | 35 | 25 | 3.1 | 21.7 |

## US regions

## Holstein regional averages (2005 breedings)

| Region | Calving
to 1st breeding
(d) | 70-day
NRR for
1st service
(%) | CR
(%) | Services
per
lactation
(no.) |  |
| --- | --- | --- | --- | --- | --- |
| Mideast | 92 |  |  |  |  |
| Midwest | 86 |  |  |  |  |
| Mountain | 93 |  |  |  |  |
| Northeast | 85 |  |  |  |  |
| Northwest | 76 |  |  |  |  |
| Southeast | 89 |  |  |  |  |
| Southwest | 73 |  |  |  |  |

## Holstein regional averages (2005 breedings)

| Region | Calving
to 1st breeding
(d) | 70-day
NRR for
1st service
(%) | CR
(%) | Services
per
lactation
(no.) |  |
| --- | --- | --- | --- | --- | --- |
| Mideast | 92 | 47 |  |  |  |
| Midwest | 86 | 46 |  |  |  |
| Mountain | 93 | 48 |  |  |  |
| Northeast | 85 | 46 |  |  |  |
| Northwest | 76 | 42 |  |  |  |
| Southeast | 89 | 44 |  |  |  |
| Southwest | 73 | 36 |  |  |  |

## Holstein regional averages (2005 breedings)

| Region | Calving
to 1st breeding
(d) | 70-day
NRR for
1st service
(%) | CR
(%) | Services
per
lactation
(no.) |  |
| --- | --- | --- | --- | --- | --- |
| Mideast | 92 | 47 | 29 |  |  |
| Midwest | 86 | 46 | 30 |  |  |
| Mountain | 93 | 48 | 27 |  |  |
| Northeast | 85 | 46 | 31 |  |  |
| Northwest | 76 | 42 | 29 |  |  |
| Southeast | 89 | 44 | 23 |  |  |
| Southwest | 73 | 36 | 27 |  |  |

## Holstein regional averages (2005 breedings)

| Region | Calving
to 1st breeding
(d) | 70-day
NRR for
1st service
(%) | CR
(%) | Services
per
lactation
(no.) |  |
| --- | --- | --- | --- | --- | --- |
| Mideast | 92 | 47 | 29 | 2.7 |  |
| Midwest | 86 | 46 | 30 | 2.7 |  |
| Mountain | 93 | 48 | 27 | 2.8 |  |
| Northeast | 85 | 46 | 31 | 2.6 |  |
| Northwest | 76 | 42 | 29 | 2.8 |  |
| Southeast | 89 | 44 | 23 | 3.0 |  |
| Southwest | 73 | 36 | 27 | 2.8 |  |

## Benefits of improved reproduction

**Lowers your semen cost **
**Optimizes cows lifetime yields **
**Reduced culling due to delayed or failed conception, i.e. less need for herd replacements**
**Provides more herd replacements**

## Two tall tales

**Reproduction is only a management issue **
**Genetics cannot help solve fertility problems**** **

## Reproductive evaluations

**Fertility of bull as a service sire **
**Fertility of bulls’ daughters when they reach breeding age**** **

## Bull fertility evaluations

**Estimated Relative Conception Rate (ERCR)**
**70-day nonreturn rate (NRR) Source:**
**DRMS (Raleigh, NC), 1986−2005**
**USDA (Beltsville, MD), 2006−present**
**Western Bull Fertility Analysis**
**75-d veterinary-confirmed conception rate **
**Source: AgriTech (Visalia, CA), 2003 −present**

## ERCR distribution (Aug. 2007)

## New service sire evaluation coming

**Based on conception rate rather than NRR**
**More accurate**
**Inseminations from most of the United States**
**All services (not just first)**
**Additional model effects included**
**Available in late Spring/Summer 2008**

## Pregnancy rate (PR)

**Percentage of open cows between 50 and 250 days in milk that become pregnant during each 21-day period**
**Advantages over days open (DO), the days from calving to conception**
**Easily defined**
**Information from nonpregnant cows included**
**Larger values preferable**

## Pregnancy rate (PR)

**PR = [21/(DO − voluntary waiting period + 11)]100**
**Voluntary waiting period assumed to be 60 days**
**Factor of +11 adjusts to middle day of 21-day cycle**
***Examples***
**Herd with average of 70 DO has PR of 100%**
**Herd with average of 91 DO has PR of 50%**
**Herd with average of 133 DO has PR of 25%**
**Herd with average of 154 DO has PR of 20%**

## USDA pregnancy rate

**Linear approximation**
**PR = 0.25 (233 − DO)**
**1% higher PR = 4 days fewer open**

## Reproductive evaluations

**Fertility of bulls’ daughters when they reach breeding age**** **

## Daughter pregnancy rate (DPR)

**First USDA genetic evaluations in 2003**
**Same across-breed animal model as for yield traits, productive life (PL), and somatic cell score (SCS)**
**Heritability of 4%**

## DPR (continued)

**Predicted transmitting abilities (PTAs) reported as percentages**
**Daughters of bull with PTA DPR of 1 expected to be 1% more likely to become pregnant during estrous cycle than if bull had PTA DPR of 0 **
**Each increase of 1% in PTA DPR equals a decrease of 4 days in PTA DO**
**PTA DO approximated by −4 ****× ****PTA DPR**
***Example:***** Bull with PTA DPR of +2.0 would have PTA DO of −8**

## Current breed averages

| Breed | PR (%) | DO (d) | Gestation length (d) | Calving interval (d) |
| --- | --- | --- | --- | --- |
| Ayrshire | 23.2 | 140 |  282 | 422 |
| Brown Swiss | 20.3 | 152 |  288 | 440 |
| Guernsey | 19.1 | 157 |  286 | 443 |
| Holstein | 22.0 | 145 |  280 | 425 |
| Jersey | 26.4 | 127 |  280 | 407 |
| Milking
   Shorthorn | 24.8 | 134 |  281 | 415 |

## DPR trend (August 2007 base)

## Bull PTA DPR frequency (Aug. 2007)

## Lifetime merit indexes

| Trait | Units | Relative value (%) |  |  |
| --- | --- | --- | --- | --- |
|  |  | Net
merit | Cheese 
merit | Fluid
merit |
| Protein | Pounds | 23 | 28 | 0 |
| Fat  | Pounds | 23 | 18 | 23 |
| Milk | Pounds | 0 | −12 | 24 |
| PL | Months | 17 | 13 | 17 |
| SCS | Log | −9 | −7 | −9 |
| Udder | Composite | 6 | 5 | 6 |
| Feet/legs | Composite | 3 | 3 | 3 |
| Body size | Composite | −4 | −3 | −4 |
| DPR | Percent | 9 | 7 | 8 |
| Calving ability | Dollars | 6 | 4 | 6 |

## Lifetime value

**Factors in determining economic value to DPR**
**Loss of about $1.50/DO**
**2.8 lactations per cow**
**No breedings for half of cows during final lactation**
**Correlation of heifer and cow fertility (0.3)**
**Value of extra calves**
**Other unmeasured health expenses**
**Total lifetime merit value of $21/PTA DPR unit**

## Genetic merit of high-DPR Holstein bulls

| Trait | All active
AI bulls |  |  |  |
| --- | --- | --- | --- | --- |
| Bulls (no.) | 684 |  |  |  |
| PTA milk (lb) | 838 |  |  |  |
| PTA fat (lb) | 32 |  |  |  |
| PTA protein (lb) | 25 |  |  |  |
| PTA SCS | 2.94
 |  |  |  |
| PTA PL (mo) | 1.1 |  |  |  |
| PTA DPR (%) | −0.4 |  |  |  |
| PTA DO (derived) | 1.6 |  |  |  |
| Net merit ($) | 242 |  |  |  |
| Semen price ($/unit) | 24 |  |  |  |

## Genetic merit of high-DPR Holstein bulls

| Trait | All active
AI bulls | Active AI
bulls with
PTA DPR
of ≥2.0 % |  |  |
| --- | --- | --- | --- | --- |
| Bulls (no.) | 684 | 41 |  |  |
| PTA milk (lb) | 838 | 287 |  |  |
| PTA fat (lb) | 32 | 14 |  |  |
| PTA protein (lb) | 25 | 17 |  |  |
| PTA SCS | 2.94 | 2.86
 |  |  |
| PTA PL (mo) | 1.1 | 4.2 |  |  |
| PTA DPR (%) | −0.4 | 2.5 |  |  |
| PTA DO (derived) | 1.6 | −10.0 |  |  |
| Net merit ($) | 242 | 346 |  |  |
| Semen price ($/unit) | 24 | 25 |  |  |

## Genetic merit of high-DPR Holstein bulls

| Trait | All active
AI bulls | Active AI
bulls with
PTA DPR
of ≥2.0 % | Top 50% of active AI bulls based on lifetime net merit
(>$245) |  |
| --- | --- | --- | --- | --- |
| Bulls (no.) | 684 | 41 | 342 |  |
| PTA milk (lb) | 838 | 287 | 1,125 |  |
| PTA fat (lb) | 32 | 14 | 43 |  |
| PTA protein (lb) | 25 | 17 | 34 |  |
| PTA SCS | 2.94 | 2.86 | 2.88
 |  |
| PTA PL (mo) | 1.1 | 4.2 | 2.1 |  |
| PTA DPR (%) | −0.4 | 2.5 | −0.1 |  |
| PTA DO (derived) | 1.6 | −10.0 | 0.4 |  |
| Net merit ($) | 242 | 346 | 357 |  |
| Semen price ($/unit) | 24 | 25 | 25 |  |

## Genetic merit of high-DPR Holstein bulls

| Trait | All active
AI bulls | Active AI
bulls with
PTA DPR
of ≥2.0 % | Top 50% of active AI bulls based on lifetime net merit
(>$245) | Top 50% of active AI bulls
based on net merit with PTA DPR of ≥2.0%  |
| --- | --- | --- | --- | --- |
| Bulls (no.) | 684 | 41 | 342 | 20 |
| PTA milk (lb) | 838 | 287 | 1,125 | 735 |
| PTA fat (lb) | 32 | 14 | 43 | 31 |
| PTA protein (lb) | 25 | 17 | 34 | 30 |
| PTA SCS | 2.94 | 2.86 | 2.88 | 2.84
 |
| PTA PL (mo) | 1.1 | 4.2 | 2.1 | 5.1 |
| PTA DPR (%) | −0.4 | 2.5 | −0.1 | 2.6 |
| PTA DO (derived) | 1.6 | −10.0 | 0.4 | −10.4 |
| Net merit ($) | 242 | 346 | 357 | 476 |
| Semen price ($/unit) | 24 | 25 | 25 | 26 |

## What if I follow the Recommendations... 

**Question: What happens if folks selects for one of those fitness traits we provide? **
**Issue: Before 1994 there was an academic discussion on what happens if we lower the SCS too much, and then cows have to face a mastitis challenge?**
**We proceeded providing PTA SCS and built it into Net Merit so theoretically there is potential for this issue to still be questioned!**

## Research the potential problem 

**Using field data less costly; using research herds would be expensive **
**Group all AI Holstein bulls with 35 or more daughters into 5 equal groups based on PTA SCS**
**Look at data across 2 generations (sire and maternal grandsire (MGS))**

## Mean daughter 1st lactation age-adjusted SCS by sire-mgs PTA SCS group

|  | Sire PTA SCS |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA SCS | ≤2.85 | 2.86 to 2.94  | 2.95 to 3.02 | 3.03 to 3.13 | ≥3.1 |
|  | Age-adjusted SCS |  |  |  |  |
| ≤2.85 | 2.77 | 2.89 | 2.97 | 3.05 | 3.22 |
| 2.86 to 2.94 | 2.82 | 2.96 | 3.03 | 3.12 | 3.29 |
| 2.95 to 3.02 | 2.88 | 3.00 | 3.08 | 3.18 | 3.35 |
| 3.03 to 3.13 | 2.89 | 3.04 | 3.13 | 3.22 | 3.40 |
| ≥3.14 | 2.96 | 3.08 | 3.19 | 3.29 | 3.46
 |

## Productive life mean (mo) by sire-mgs PTA SCS group

|  | Sire PTA SCS |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA SCS | ≤2.85 | 2.86 to 2.94  | 2.95 to 3.02 | 3.03 to 3.13 | ≥3.1 |
|  | PL (mo) |  |  |  |  |
| ≤2.85 | 28.2 | 28.0 | 27.4 | 27.2 | 26.4 |
| 2.86 to 2.94 | 28.3 | 28.0 | 27.4 | 27.3 | 26.3 |
| 2.95 to 3.02 | 27.9 | 27.5 | 27.0 | 26.8 | 25.9 |
| 3.03 to 3.13 | 28.0 | 27.4 | 26.9 | 26.6 | 25.8 |
| ≥3.14 | 27.4 | 27.1 | 26.6 | 26.4 | 25.2 |

## Productive life deviation (mo) by sire-mgs PTA SCS group

|  | Sire PTA SCS |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA SCS | ≤2.85 | 2.86 to 2.94  | 2.95 to 3.02 | 3.03 to 3.13 | ≥3.1 |
|  | PL (mo) |  |  |  |  |
| ≤2.85 | +3.2 | +2.8 | +2.3 | +2.2 | +1.2 |
| 2.86 to 2.94 | +3.1 | +2.7 | +2.1 | +2.1 | +1.0 |
| 2.95 to 3.02 | +2.9 | +2.3 | +1.9 | +1.8 | +0.8 |
| 3.03 to 3.13 | +2.9 | +2.3 | +1.8 | +1.6 | +0.6 |
| ≥3.14 | +2.4 | +1.8 | +1.4 | +1.2 | 0.0 |

## Percent of cows culled for mastitis by sire-mgs PTA SCS group

|  | Sire PTA SCS |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA SCS | ≤2.85 | 2.86 to 2.94 | 2.95 to 3.02 | 3.03 to 3.13 | ≥3.14 |
|  | (% culled) |  |  |  |  |
| ≤2.85 | 8.6 | 9.2 | 9.6 | 10.5 | 11.6 |
| 2.86 to 2.94 | 8.9 | 9.4 | 10.3 | 11.0 | 11.9 |
| 2.95 to 3.02 | 9.0 | 9.8 | 10.0 | 11.3 | 12.3 |
| 3.03 to 3.13 | 9.6 | 9.9 | 10.7 | 11.6 | 12.8 |
| ≥3.14 | 9.9 | 10.6 | 11.0 | 12.1 | 13.4 |

## Productive life mean (mo) by sire-mgs PTA DPR group

|  | Sire PTA DPR |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA DPR | ≤-1.2 | -1.1 to -0.4 | -0.3 to 0.3 | 0.4 to 1.1 | ≥1.2 |
|  | PL (mo) |  |  |  |  |
| ≤-1.2 | 25.0 | 26.2 | 26.4 | 27.3 | 28.7 |
| -1.1 to -0.4 | 25.6 | 26.8 | 26.9 | 27.8 | 29.0 |
| -0.3 to 0.3 | 25.6 | 26.8 | 26.9 | 27.9 | 29.0 |
| 0.4 to 1.1 | 26.1 | 27.5 | 27.4 | 28.2 | 29.4 |
| ≥1.2 | 26.4 | 27.8 | 27.9 | 28.7 | 29.5 |

## Productive life deviation (mo) by sire-mgs PTA DPR group

|  | Sire PTA DPR |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA DPR | ≤-1.2 | -1.1 to -0.4 | -0.3 to 0.3 | 0.4 to 1.1 | ≥1.2 |
|  | PL (mo) |  |  |  |  |
| ≤-1.2 | -4.2 | -3.0 | -2.9 | -2.1 | -0.8 |
| -1.1 to -0.4 | -3.8 | -2.5 | -2.5 | -1.7 | -0.6 |
| -0.3 to 0.3 | -3.7 | -2.5 | -2.5 | -1.6 | -0.6 |
| 0.4 to 1.1 | -3.3 | -1.9 | -2.2 | -1.4 | -0.3 |
| ≥1.2 | -2.8 | -1.5 | -1.7 | -0.9 | 0.0 |

## Percent of cows culled for reproductive reasons by sire-mgs PTA DPR group

|  | Sire PTA DPR |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| MGS PTA DPR | ≤-1.2 | -1.1 to -0.4 | -0.3  to 0.3 | 0.4 to 1.1 | ≥1.2 |
|  | (% culled) |  |  |  |  |
| ≤-1.2 | 13.3 | 12.8 | 12.5 | 11.8 | 11.3 |
| -1.1 to -0.4 | 12.8 | 12.3 | 12.2 | 11.4 | 10.9 |
| -0.3 to 0.3 | 12.7 | 12.2 | 12.0 | 11.2 | 10.8 |
| 0.4 to 1.1 | 12.2 | 11.7 | 11.6 | 10.8 | 10.4 |
| ≥1.2 | 11.8 | 11.3 | 11.0 | 10.6 | 10.0 |

## Conclusions

**H.D. Norman**

**NDHIA San Antonio (****)**

**Conclusions**

## Recommendations to breeders 

**Usual recommendation: Don’t select bulls solely on one trait because many traits have economic value **
**Consider economic value of all performance traits in your own market when making genetic choices**
**Dairies with seasonal calving should find an index that puts more weight on daughter fertility than those recommended for the general industry**

## Selection for bull fertility

**Breeding to bulls with higher conception rates returns a profit fairly quickly**
**Premium of $2 could be paid for semen per 1% improvement in fertility**
**Thus, a unit of semen from bull with ERCR of +2 is worth $8 more than a unit from bull with ERCR of −2**
**Use bull fertility as a secondary selection trait after picking bulls on their economic indexes**

## Selection for cow fertility

**Selection for improved fertility will pay off, even though the benefit is delayed for 3 years**
**Choose your sires based on lifetime economic merit that includes daughter fertility, rather than for daughter fertility alone**
**However, producers with herd fertility problems could emphasize DPR extensively with little loss in overall net merit**

## Fertility emphasis

**Service-sire fertility and DPR especially important for grazing herds with seasonal calving**
**Use of a few bulls that average 3.0% for PTA DPR (equivalent to a decrease of 12 DO) could neutralize much of genetic decline in fertility from use of high-yield bulls for 40 years**
**Select for overall merit based on genetic-economic index appropriate for your situation **

## Thank you!

***Thank you!***