1. Breeding Objectives for Terminal Sires Michael MacNeil USDA ARS Miles City, MT

2. Acknowledgements John Stewart-Smith Scott Newman William Herring Larry Benyshek

3. Single-Trait EPD or EBV Predicts heritable differences among animals for individual traits

4. Milk EPD, peak yield, and total milk production from Line 1 Hereford cows MilkEPD, kg Peak, kg/d Total, kg -10 5.0 697 - 5 5.9 819 0 6.8 940 5 7.7 1062 10 8.5 1183 Do EPD and EBV work? YES!

5. Animal Improvement Systems Breeding Objective Selection Criteria Dissemination System Economic Analysis Goal Breeding Scheme Design Mating Plan What to change What to measure Who to measure What is net worth of change What to do with good ones Garrick

6. Genetic Merit

7. EPD / Acc Difference

8. Commercial Producers Capture heterosis –25% increased output –3% increased input –>$100/cow/year increased net return Use complimentary –Locally adapted maternal breeds –Terminal sires

9. Objective Discuss derivation of breeding objectives for terminal sires

10. Sire Selection It is always about predicting the future!

11. Model production system

12. Phenotypes –Reproduction – Pregnancy rate and calf survival –Growth – Direct and maternal effects preweaning direct effects postweaning –Feed Intake – Cow herd (size and milk) and feedlot –Carcass – Multivariate normal distribution weight, marbling and cutability

13. Breeding Systems –Straightbred Angus females Angus, Simmental –2-breed rotation females British x British: Limousin, Charolais British x Continental: Hereford

14. Economics –Monitor costs for cow-calf and feedlot phases of production –Derive returns from carcass beef with price discrimination based on carcass merit

15. Economically Relevant Traits –Sensitivity analysis to determine traits of terminal sires that affect profitability of production system –Economically relevant traits (ERT) are those that change profit

16. Means of traits of economic importance in selection of terminal sires Phenotypes of economic importance Breed SVWW(d)ADGFIDPYGMS Angus945503.4326.8633.55.4 Charolais956163.7328.2622.14.5 Hereford935523.4325.2623.35.0 Limousin945763.4125.3651.94.4 Simmental916123.7725.9632.34.8

17. Post-weaning Management PeriodEndpointFeed Cost ¢/lb Yardage $/d Energy Fed ME/lb 1850 lbs3.50.301.1 2+50 d4.00.301.4 3+100 d6.00.351.5

18. Basis of price discrimination among Angus sired carcasses Base Price $121 / cwt TraitPremiums and Discounts Weight< 550 lbs = -$20>950 lbs = -$20 Quality Grade Prime $9.00 High Choice $5.00 Low Choice $3.70 Select -$5.60 Standard -$15.00 Yield Grade1: $4.002: $1.503: $0.004: -$15.005: -$20.00

19. Basis of price discrimination among Charolais sired carcasses Base Price $115 / cwt TraitPremiums and Discounts Weight< 550 lbs = -$19.90>950 lbs = -$16.80 Quality Grade Prime $6.50 High Choice $1.30 Low Choice $3.70 Select -$6.20 Standard -$17.00 Yield Grade1: $3.102: $2.003: -$1.004: -$14.505: -$19.50

20. Basis of price discrimination among Hereford sired carcasses Base Price $121 / cwt TraitPremiums and Discounts Weight< 550 lbs = -$17.50>950 lbs = -$12.75 Quality Grade Prime $7.25 High Choice $3.25 Low Choice $0.00 Select -$4.50 Standard -$18.00 Yield Grade1: $3.002: $2.253: $0.004: -$15.005: -$20.00

21. Basis of price discrimination among Limousin sired carcasses Base Price $121 / cwt TraitPremiums and Discounts Weight< 550 lbs = -$20.00>950 lbs = -$20.00 Quality Grade Prime $7.00 High Choice $2.50 Low Choice $0.00 Select -$10.00 Standard -$20.00 Yield Grade1: $4.002: $2.003: -$1.004: -$15.005: -$20.00

22. Basis of price discrimination among Simmental sired carcasses Base Price $121 / cwt TraitPremiums and Discounts Weight< 550 lbs = -$20.00>950 lbs = -$20.00 Quality Grade Prime $9.00 High Choice $4.50 Low Choice $3.70 Select -$5.60 Standard -$15.00 Yield Grade1: $4.002: $1.503: $0.004: -$15.005: -$20.00

23. From model to breeding objective

24. Calculations –Determines partial derivative ( d ) of profit with respect to each ERT –Breeding objective H = ∑ d i G i after Hazel (1943) I = ∑ d i EBV i Henderson (1951)

25. Breeding objectives for terminal sires ERTANCHHFLNSM Survival, %1096733784736868 WW(d), kg130145138146102 ADG, kg/d89565564671972764082 Feed Intake, kg/d-3546-4074-2644-2552-2646 Dressing %29383319267427601131 Yield Grade-10149-284-5896-2986-4120 Marbling Score476158402454901764

26. Economic values relative to genetic variation ERTANCHHFLNSM Survival, %32392167231721752566 WW(d), kg35733985379240122803 ADG, kg/d1746108513011418796 Feed Intake, kg/d-2952-3391-2201-2124-2203 Dressing %27973159254526271077 Yield Grade-2742-77-1593-807-1113 Marbling Score336041284038741245

27. Correlations between objectives BreedCharolaisHerefordLimousinSimmental Angus0.740.970.930.89 Charolais0.800.740.85 Hereford0.980.87 Limousin0.80

28. EPD / Acc Difference $Index = +4

29. Complications in application Not all ERT have EPD or EBV –Map ERT onto EPD or EBV following Schneeburger et al., 1992 Variation among production systems –Substantial correlations among objectives for terminal sires across somewhat different production systems

30. Change is inevitable, adaptability and survival are optional

31. Thank-you!