Genetic Selection as a Tool for Battling the Decline in Reproductive Performance: A Dairy Perspective

1. Genetic Selection as a Tool for Battling the Decline in Reproductive Performance: A Dairy Perspective Kent A. Weigel, Ph.D. Department of Dairy Science University of Wisconsin

2. Background

3. Reproduction of Lactating Cows vs. Yearling Heifers Lopez et al., 2004

4. Estrus Characteristics Lopez et al., 2004

5. Duration of Estrus Lopez et al., 2004

6. Multiple Ovulation Lopez et al., 2004

7. Twinning Rate in Holsteins Silva del Rio et al., 2006 Kinsel et al., 1998 Twinning (%) Year of Conception

8. Importance of Body Condition Score

9. Anovulatory Condition Lopez et al. 2004

10. Anovulatory Condition Lopez et al. 2004

11. Milk Yield vs. Embryonic Loss between 31 to 45 d of Pregnancy P = 0.81 Low milk = 36 kg/d High milk = 52 kg/d Santos et al., 2004

12. Body Condition vs. Embryonic Loss N=250 P < 0.05 N=147 N=103 Silke et al., 2004

13. Selection for Female Fertility

14. Indirect Selection for Fertility Length of Productive Life(available since 1994) Total months in milk by 7 years of age Limit of 10 months per lactation Rewards a short calving interval Dairy Form(received negative economic weight in 2005) Poor body condition = poor fertility Can measure milk production directly Shouldn’t reward angularity

15. Evaluation of Female Fertility USDA Animal Improvement Programs Laboratory introduced national genetic evaluations for female fertility in 2003  Dairy sires from all breeds are evaluated based on the fertility of their daughters  The animal model system for fertility is the same as for production traits  Evaluations are released 3 times per year

16. Evaluation of Female Fertility  Input data are days open measurements from the DHI milk recording system  Days open (calculated from the last reported insemination) is confirmed with subsequent calving dates, if possible  Animals with no subsequent calving are assigned an arbitrary value of 250 days  Days open data are transformed to 21-day pregnancy rates

17. Today’s Fertility Data  Introduced in February 2003 > 40 million records > 16 million cows  Based on days open data, including:  Breeding date confirmed by calving (57%)  Breeding date without next calving (19%)  Breeding date conflicts with next calving (5%)  Next calving, but no reported breeding (6%)  Culled due to infertility (5%)  No fertility information (8%)  Published “daughter pregnancy rate”

18. Example Bulls for DPR 1H6360 Wizard DPR +3.7% 200H3101 Freelance DPR -3.8% 1% DPR ≈ 4 days open The 21-day pregnancy rate of Wizard daughters will be 7.5% higher, on average than for Freelance daughters, and Wizard daughters will have 30 fewer days open per lactation

19. Genetic Trend in Milk Yield Genetic Correlation = 0.31 Introduction of Productive Life Genetic Trend in Daughter Pregnancy Rate

20. Selection forMale Fertility

21. Evaluation of Male Fertility  Regional evaluations of male fertility have been carried out by dairy records processing centers for many years  USDA-AIPL recently began computing “phenotypic” evaluations for service sire conception rate (i.e., direct effect)  Evaluations are published as the expected percentage change in conception rate, including both genetic and environmental factors

22. Example Bulls for SCR 29H10483 Jammer SCR + 4 9,731 inseminations 14H4099 Billion SCR - 3 4,422 inseminations Expect a 7% difference between these bulls in conception rate, under equivalent management conditions

23. Additional Fertility Traits  As a by-product of evaluations for service sire conception rate, two new female fertility traits were introduced in 2009  Cow conception rate measures the expected difference in conception rate due to the female (i.e., maternal effect) in lactating animals  Heifer conception rate measures the expected difference in conception rate in non-lactating animals

24. National Fertility Database USDA Format 5

25. Selection for Animal Health

26. Pregnancy Risk by Calving Disorder Risk of Pregnancy Calving Disorder

27. Stillbirths and Female FertilityBicalho et al. (2007)

28. Pregnancy Risk by Repro. Disorder Risk of Pregnancy Reproductive Disorder (in 1st 75 d Postpartum)

29. Pregnancy Risk by Mastitis Infection Risk of Pregnancy Mastitis Infection (in 1st 75 d Postpartum)

30. Pregnancy Risk by Metabolic Disorder Risk of Pregnancy Metabolic Disorder (in 1st 75 d Postpartum)

31. Pregnancy Risk by Mobility Disorder Risk of Pregnancy Mobility Disorder (in 1st 75 d Postpartum)

32. Management Software Dairy Comp 305  Valley Ag Software, Tulare, CA  ~ 4,000 large herds PCDART  DRMS, Raleigh, NC  ~ 3,000 medium-sized herds DHI-Plus®  DHI-Provo, Provo, UT  ~ 300 very large herds

33. Disease Codes

34. Summary of the Data(Alta Advantage herds and selected DRMS herds) Zwald et al., 2004

35. Heritability Estimates Zwald et al., 2004

36. Predicted Transmitting Abilities for Daughter Health Zwald et al., 2004

37. Challenges with Health Traits •Differences in exposure •e.g., mastitis pathogens •Inconclusive test results •e.g., Johne’s disease •Incomplete reporting •incorrect diagnosis •underestimated severity •selective treatment •temporary recording •Restrictions on access to the data

38. National Health Database USDA Format 6

39. Lifetime Net Merit (NM$) 23% Fat 23% Protein 17% Productive Life -9% Somatic Cell Score 6% Udder Composite 3% Feet & Legs Composite -4% Body Size Composite 9% Daughter Pregnancy Rate 6% Calving Ability

40. Impact of Crossbreeding

41. Breed Differences (vs. Holstein) Genetic differences between breeds represent twice the difference in average predicted transmitting ability (PTA) from the USDA-AIPL multi-breed genetic evaluations

42. Fertility of Crossbred Cows (Heins et al., 2006) fertility during1st lactation Different from pure Holsteins: † P<0.10, * P<0.05, ** P<0.01

43. Fertility and Udder Health of Crossbred Cows (Dechow et al., 2007) Different superscripts within a row indicate Statistical significance at the P<0.05 level

44. Longevity of Crossbred Cows (Heins et al., 2006) survival during1st lactation survival until 2nd calving Different from pure Holsteins: † P<0.10, * P<0.05, ** P<0.01

45. UW-Madison Dairy Science…Committed to Excellence in Research, Extension and Instruction http://www.wisc.edu/dysci Any Questions?