# Presentation: 005218

## Genetic Evaluation of Cow Fertility Using DHIA Records

## History of DHIA Data

| Trait | Collected since | Evaluated since |
| --- | --- | --- |
| Milk and fat yield | 1908 | 1935 |
| Protein yield | 1975 | 1977 |
| Calving ease | 1980 (DHIA) | 1978 (NAAB) |
| Somatic cell score | 1987 | 1994 |
| Calving interval | 1908 | 2003 |

## Factors Affecting Fertility

**Environment and management**
**Season, region, herd, age**
**Milk yield, voluntary waiting period**
**Fertility of service sire ****(ERCR)**
**Genes of cow ****(DPR)**
**Interaction of bull and cow**
**Inbreeding, recessives ****(CVM)**

## Introduction

**Cow fertility has declined over time.**
**Higher yields cause more days open**
**Genetic evaluations expressed as daughter pregnancy rate ****(DPR)**** instead of days open.**

## Pregnancy Rate

**The percentage of non-pregnant cows that become pregnant during each 21-day period**
**Pregnancy rate < conception rate**
**Non-cycling cows**
**Estrus not expressed or detected**
**Typical pregnancy rates**
**20%**** if herd averages ****154**** days open**
**25%**** if herd averages ****133**** days open**

## Pregnancy Rate and Days Open

**Pregnancy Rate and Days Open**

**0**

**10**

**20**

**30**

**40**

**50**

**60**

**70**

**80**

**90**

**100**

**60**

**81**

**102**

**123**

**144**

**165**

**186**

**207**

**228**

**249**

**Number of Chances**

**Pregnancy Rate**

**9**

**8**

**7**

**6**

**5**

**4**

**3**

**2**

**1**

**Days Open**

## Pregnancy Rate Formulas

**Can be derived from days open**
**Non-linear: ****21 / (DO – VWP + 11)**
**Linear approx: ****(233 – DO) / 4**
**Advantages over days open**
**Positive numbers are desirable**
**Earlier measure of herd fertility**

**Notes:**
VWP = Voluntary waiting period

## Phenotypic Trend – Holstein DO

**5****th**

**4****th**

**3****rd**

**2****nd**

**1****st**

**Lactation**

## Days Open Trends

**Phenotypic trend 1960 - 1998 **
**Holstein:****	****+37**** days**
**Jersey:****	****+20**** days **
**Genetic trend 1960 - 1998 **
**Holstein:****	****+17 ****days **
**Jersey:****	****+9**** days **
**Expected correlated response**
**Milk trend ****x**** .38 correlation = ****+17**** days**

## Distribution of Days OpenHolstein Calvings 1990 - 2001

**≤**** ****50**

**≥**** ****250**

**Distribution of Days Open****Holstein Calvings 1990 - 2001**

**Cows culled for reproductive reasons**

## Evaluation Methods

**Same programs used for yield, PL, SCS**
**Convert to preg rate = (233 – DO) / 4**
**Parameter estimates used:**
**Heritability = ****4%**
**Repeatability = ****11%**
**Sire-by-herd interaction = ****1%**
**Adjust for regional, seasonal, herd, and age differences**

## Seasonal Effects on Days OpenHolsteins calving since 1997 in each US region

## Pregnancy Rate Evaluation

**Lactations 1-5 beginning with 1960**
**Data sources**
**Reported DO confirmed with next calving**
**Reported DO if no next calving**
**Calving interval – 280 days if no reported DO**
**Assigned DO = 250 if sold for infertility**

## Sources of Fertility Data 1998-1999

|  | AY | BS | GU | HO | JE | MS |
| --- | --- | --- | --- | --- | --- | --- |
| Breeding date verified    by calving date | 55 | 54 | 48 | 57 | 64 | 53 |
| Breeding date disagrees with calving date | 6 |  8 |  8 |  5 |  5 |  8 |
| Breeding date but no next calf | 16 | 15 | 20 | 19 | 17 | 16 |
| No breeding reported, only next calf |   7 |  9 |  8 |  6 |  6 | 11 |
| Cows sold for reproductive problems |   6 |  5 |  5 |  5 |  3 |  4 |
| No information for fertility | 10 |  9 | 11 |  8 |  5 |  8 |

**Sources of Fertility Data 1998-1999**

## Genetic Evaluation

**Holstein data from February 2003 evaluation**
**40 million**** lactations**
**16 million**** cows**
**Statistics for recent AI bulls **
**Born 1994 – 1998**
**Reliability averages**
**DPR 59%**
**PL 61%**
**SCS 69%**
**Milk 85%**

## Older Bull Evaluations

|  | REL | DO | DPR | PL | NM$ |
| --- | --- | --- | --- | --- | --- |
| Duster | 99 | - 10 | +2.4 | +4.3 | +453 |
| Bellwood | 99 | - 1 | +0.2 | -0.5 | +356 |
| Mandel | 99 | + 7 | - 1.8 | -0.7 | +244 |
| Luke | 99 | + 10 | - 2.4 | -1.8 | +132 |
| Mountain | 99 | - 4 | +1.0 | +1.1 | +283 |
| Mascot | 99 | + 3 | - 0.8 | -2.9 | +29 |

**Notes:**
DO = Days Open
DPR = Daughter Pregnancy Rate

## Pregnancy Rate Genetic Trend 1957-1999

## Bulls ranked by Net MeritFebruary 2003

|  |  DPR | PL | Net Merit $  |
| --- | --- | --- | --- |
| Vision-Gen Ozzie  |  0.1 | 0.9 | 680 |
| Win.-Manor Machoman |  0.9 | 2.8 | 647 |
| Ricecrest Marshall | -1.6 | 0.1 | 644 |
| Carol Prelude Mtoto | -1.6 | 2.6 | 627 |
| Welcome Garter | -1.4 | 0.8 | 620 |
| Shipsholm Glenwood |  0.7 | 2.1 | 600 |
| McCloe-Pond Trent |  0.4 | 0.7 | 597 |
| Pagen-Ernwood Dane | -1.3 | 1.1 | 595 |

## Bulls with High Daughter Fertility 

|  |      DPR |         PL | REL DPR | REL PL |
| --- | --- | --- | --- | --- |
| Dixellen Design | 2.6 | 0.3 | 93 | 94 |
| KRansom D Event | 2.6 | 4.9 | 65 | 67 |
| HA Sky.  George | 2.4 | 2.8 | 56 | 60 |
| Pen Col Duster | 2.4 | 4.4 | 99 | 99 |
| M.  Infinity Aruba | 2.3 | 0.1 | 69 | 72 |
| Start.  Rudolph | 2.2 | 2.8 | 99 | 99 |
| Boulet Charles | 2.2 | 2.6 | 99 | 99 |

## Bulls with Low Daughter Fertility 

|  |      DPR |         PL | REL DPR | REL PL |
| --- | --- | --- | --- | --- |
| Kemview Beauty | - 4.1 |   2.4 | 65 | 70 |
| W. Boy Wonder | - 3.2 | - 1.4 | 75 | 79 |
| D. Luke Champ | - 3.2 | - 2.1 | 78 | 68 |
| Ricecrest Lance | - 3.1 | - 2.3 | 91 | 82 |
| S. Star Hi Metro | - 3.1 |   0.8 | 69 | 72 |
| W. Del Convincer | - 3.1 |   1.1 | 93 | 80 |
| Kemview Curtis | - 3.0 | - 0.1 | 48 | 50 |

## Summary

**Daughter Pregnancy Rate has low heritability (****~4%****) but high genetic correlation with Productive Life (****>.5****)**
**Official evaluations of DPR began  February 2003.**
**Selection on PL has helped to reduce the decline in cow fertility.**

## Future Directions

**Daughter Pregnancy Rate will be included in Net Merit.**
**New “Format 5” fertility data**
**Store all breedings, not just last**
**Store service sire identification**
**Pregnancy checks (began 2002)**
**New “Format 6” health trait data**

## Thank You!

**DHIA was my first employer (Ogle county, IL, 1976-1978).**
**AIPL staff contributed greatly. We now use more data provided by ****YOU****  through DHIA.**
**Most producers report accurate breeding dates.**
**More complete information is always welcome.**

## AIPL Web Siteaipl.arsusda.gov

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