1. XX International Grassland Conference 2005 (1) 2005 Genetic Alternatives for Dairy Producers who Practise Grazing H. D. Norman, J. R. Wright, R. L. Powell Animal Improvement Programs Laboratory Agricultural Research Service, USDA Beltsville, MD 20705-2350 dnorman@aipl.arsusda.gov 301-504-8334

2. What genetic programs work well for U.S. graziers? XX International Grassland Conference 2005 (2)

3. XX International Grassland Conference 2005 (3) Grazier breeding l Objective – Cattle with better fertility or other desired characteristics l Approaches (occasional use) – Bulls from countries that practise grazing – Bull breed different from cow breed – Effectiveness?

4. XX International Grassland Conference 2005 (4) Phenotypic trend in days open 1 2 3 4 5 Lactation

5. XX International Grassland Conference 2005 (5) Comparison l Daughter performance within herd – New Zealand AI Holstein or Friesian bulls – Other AI Holstein bulls (predominantly U.S.) l Cows included – Records in AIPL national database – Calved before March 2004 – Time to express the performance traits

6. XX International Grassland Conference 2005 (6) Yield and SCS data l First-lactation daughters (149 herds) – 489 sired by New Zealand bulls – 5419 sired by U.S. bulls l Second-lactation daughters (126 herds) – 345 sired by New Zealand bulls – 5057 sired by U.S. bulls l Third-lactation daughters (78 herds) – 174 sired by New Zealand bulls – 2840 sired by U.S. bulls

7. XX International Grassland Conference 2005 (7) Yield results l Milk U.S. daughter superiority – First lactation501 kg*** – Second lactation467 kg*** – Third lactation448 kg*** l FatNew Zealand daughter advantage – First lactation2 kg – Second lactation 2 kg – Third lactation2 kg l ProteinU.S. daughter superiority/advantage – First lactation 5 kg** – Second lactation 5 kg* – Third lactation 4 kg

8. XX International Grassland Conference 2005 (8) Economic value l Current U.S. milk prices l MFP$ = 0.012  milk+ 1.30  fat + 2.30  protein l U.S. daughter MFP$ advantage – First lactation$35.09 – Second lactation$30.83 – Third lactation$28.39

9. XX International Grassland Conference 2005 (9) SCS results l First lactation U.S. daughter advantage of 0.1 l Second lactation U.S. daughter superiority of 0.2*** l Third lactation U.S. daughter advantage of 0.2

10. XX International Grassland Conference 2005 (10) Days open data l First-lactation daughters (138 herds) – 450 sired by New Zealand bulls – 5036 sired by U.S. bulls l Second-lactation daughters (112 herds) – 311 sired by New Zealand bulls – 4781 sired by U.S. bulls l Third-lactation daughters (68 herds) – 146 sired by New Zealand bulls – 1939 sired by U.S. bulls

11. XX International Grassland Conference 2005 (11) Days open results l First lactation New Zealand daughter superiority of 7 days* l Second lactation U.S. daughter advantage of 2 days l Third lactation U.S. daughter advantage of 3 days

12. XX International Grassland Conference 2005 (12) Type data l First-lactation daughters (42 herds) – 76 sired by New Zealand bulls – 376 sired by U.S. bulls

13. XX International Grassland Conference 2005 (13) Type results l Size composite New Zealand daughters smaller by 0.91 points*** l Udder composite U.S. daughter advantage of 0.79 points l Foot composite U.S. daughter superiority of 0.68 points**

14. XX International Grassland Conference 2005 (14) Conclusions l Strain differences between U.S. Holsteins and New Zealand Friesians for several traits l Higher milk and protein yields for U.S. bull daughters l Lower first-lactation SCS for U.S. bull daughters

15. XX International Grassland Conference 2005 (15) Conclusions (continued) l Fewer first-lactation days open for New Zealand bull daughters l Smaller body size for New Zealand bull daughters l Better feet for U.S. bull daughters

16. XX International Grassland Conference 2005 (16) Caution All strain differences influenced by individual bulls chosen from each country

17. XX International Grassland Conference 2005 (17) Recommendations to breeders l Don’t select bulls solely on one trait because many traits have economic value l Consider economic value of all performance traits in your own market when making genetic choices l For seasonal calving, use an index that puts more weight on daughter fertility than those recommended for the general industry

18. XX International Grassland Conference 2005 (18) Alternative approaches l Comparisons needed – Productive life – Crossbreds l Advantages of either alternative

19. XX International Grassland Conference 2005 (19) Crossbreeding l Heterosis – Milk 3.4% – Fat 4.4% – Protein 4.1% – SCS  0.7% – Days open 1.8%

20. XX International Grassland Conference 2005 (20) Thank you!