2006 Mid-Atlantic Dairy Grazing Conference, 2006 (1) Is There a Need for Different Genetics in Dairy Grazing Systems? H. D. Norman, J. R. Wright, R. L. Powell Animal Improvement Programs Laboratory Agricultural Research Service, USDA Beltsville, MD

What genetic programs work well for U.S. graziers? 2006 Mid-Atlantic Dairy Grazing Conference, 2006 (2)

Mid-Atlantic Dairy Grazing Conference, 2006 (3) 2006 Grazier breeding l Objective – Cattle with better fertility or other desired characteristics l Approaches (occasional use) – Bulls from countries that practice grazing – Bull breed different from cow breed to capitalize on heterosis – Effectiveness in grazing herds?

Mid-Atlantic Dairy Grazing Conference, 2006 (4) 2006 Phenotypic trend in days open Lactation

Mid-Atlantic Dairy Grazing Conference, 2006 (5) 2006 Comparison study l Daughter performance within herd – New Zealand AI Holstein/Friesian bulls – Other AI Holstein bulls (predominantly U.S.) l Cows included – Records in AIPL national database – Calved (1 st parity) before May 2005 – Time to express the performance traits

Mid-Atlantic Dairy Grazing Conference, 2006 (6) 2006 Traits examined – Milk, fat, protein – Somatic cell score – Days open – Conformation traits

Mid-Atlantic Dairy Grazing Conference, 2006 (7) 2006 Yield and SCS data l First-lactation daughters (159 herds) – 552 sired by 26 New Zealand bulls – 6266 sired by 1119 U.S. bulls l Second-lactation daughters (136 herds) – 394 sired by 19 New Zealand bulls – 5212 sired by 1464 U.S. bulls l Third-lactation daughters (90 herds) – 213 sired by 14 New Zealand bulls – 3170 sired by 1036 U.S. bulls

Mid-Atlantic Dairy Grazing Conference, 2006 (8) 2006 Yield results l Milk U.S. daughter superiority – First lactation1060 lb*** – Second lactation1261 lb*** – Third lactation1056 lb*** l FatNew Zealand daughter advantage – First lactation2 lb – Second lactation 2 lb – Third lactation7 lb l ProteinU.S. daughter superiority/advantage – First lactation 11 lb** – Second lactation 15 lb*** – Third lactation 11 lb

Mid-Atlantic Dairy Grazing Conference, 2006 (9) 2006 Economic value l Current U.S. milk prices l MFP$ =  milk  fat  protein l U.S. daughter MFP$ advantage – First lactation$35.41 – Second lactation$46.43 – Third lactation$27.85

Mid-Atlantic Dairy Grazing Conference, 2006 (10) 2006 SCS results l First lactation U.S. daughter superiority of 0.22*** l Second lactation U.S. daughter advantage of 0.10 l Third lactation U.S. daughter advantage of 0.06

Mid-Atlantic Dairy Grazing Conference, 2006 (11) 2006 Days open data l First-lactation daughters (148 herds) – 513 sired by 25 New Zealand bulls – 5823 sired by 1078 U.S. bulls l Second-lactation daughters (122 herds) – 357 sired by 19 New Zealand bulls – 4663 sired by 1338 U.S. bulls l Third-lactation daughters (79 herds) – 183 sired by 14 New Zealand bulls – 2767 sired by 931 U.S. bulls

Mid-Atlantic Dairy Grazing Conference, 2006 (12) 2006 Days open results l First lactation New Zealand daughter superiority of 7 days* l Second lactation New Zealand daughter superiority of 8 days* l Third lactation New Zealand daughter advantage of 2 days

Mid-Atlantic Dairy Grazing Conference, 2006 (13) 2006 Type data l First-lactation daughters – 79 sired by New Zealand bulls – 308 sired by U.S. bulls

Mid-Atlantic Dairy Grazing Conference, 2006 (14) 2006 Type results l Final score U.S. daughters higher by 1.6 points* l Stature U.S. daughters taller, by 2.3 points* l Rear udder height U.S. daughter superior by 2.6 points* l Udder depth U.S. daughter superior by 3.2 points**

Mid-Atlantic Dairy Grazing Conference, 2006 (15) 2006 Yield results from spring calvers l Milk U.S. daughter superiority – First lactation 774 lb*** – Second lactation1186 lb*** – Third lactation1642 lb*** l FatNew Zealand daughter advantage – First lactation 7 lb – Second lactation 4 lb – Third lactation13 lb l ProteinU.S. daughter superiority/advantage – First lactation 9 lb – Second lactation 18 lb* – Third lactation 29 lb**

Mid-Atlantic Dairy Grazing Conference, 2006 (16) 2006 SCS results for spring calvers l First lactation U.S. daughter superiority of 0.24* l Second lactation U.S. daughter advantage of 0.16 l Third lactation U.S. daughter advantage of 0.11

Mid-Atlantic Dairy Grazing Conference, 2006 (17) 2006 Days open for spring calvers l First lactation New Zealand daughter advantage of 6 days l Second lactation New Zealand daughter advantage of 1 days l Third lactation New Zealand daughter advantage of 1 days

Mid-Atlantic Dairy Grazing Conference, 2006 (18) 2006 Genetic alternative To achieve top fertility, consider direct selection for Daughter pregnancy rate (DPR) from US bulls or those from all sources

Mid-Atlantic Dairy Grazing Conference, 2006 (19) 2006 Definitions l Days open = days from calving to conception l Daughter pregnancy rate (DPR) = percentage of those open (non- pregnant) cows that are between 50 and 250 days in milk that become pregnant within 21 days

Mid-Atlantic Dairy Grazing Conference, 2006 (20) 2006 Days open and DPR by breed l Breed Avg. days open Avg DPR (%) – Ayrshire – Brown Swiss – Guernsey – Holstein – Jersey – Milking Shorthorn DPR = 0.25 (233 – days open)

Mid-Atlantic Dairy Grazing Conference, 2006 (21) 2006 High DPR vs. Active-AI Holsteins l Traits High DPR bulls All Active-AI – Milk (lbs) – Fat (lbs)14 32 – Protein (lbs)19 26 – SCS – Productive Life (mo) – DPR (%) – Net Merit Dollars # of bulls (DPR≥2.0)24 692

Mid-Atlantic Dairy Grazing Conference, 2006 (22) 2006 High DPR vs. All Active-AI Jerseys l Traits High DPR bulls All Active-AI – Milk (lbs) – Fat (lbs)46 40 – Protein (lbs)18 27 – SCS – Productive Life (mo) – DPR (%) – Net Merit Dollars # of bulls (DPR≥1.0)11 96

Mid-Atlantic Dairy Grazing Conference, 2006 (23) 2006 Higher DPR vs. High Active-AI HO l Traits Higher DPR bulls High All Active-AI – Milk (lbs) – Fat (lbs)28 44 – Protein (lbs)29 35 – SCS – Productive Life (mo) – DPR (%) – Net Merit Dollars # of bulls (DPR≥2.0)12 346

Mid-Atlantic Dairy Grazing Conference, 2006 (24) 2006 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

Mid-Atlantic Dairy Grazing Conference, 2006 (25) 2006 Conclusions (continued) l Fewer first- and second-lactation days open for New Zealand bull daughters l Smaller body size for New Zealand bull daughters l Better udders for U.S. bull daughters

Mid-Atlantic Dairy Grazing Conference, 2006 (26) 2006 Caution l Strain differences influenced by individual bulls chosen from each country l Found the New Zealand bulls chosen were slightly more selective than the US bulls used

Mid-Atlantic Dairy Grazing Conference, 2006 (27) 2006 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

Thank you! 2006 Mid-Atlantic Dairy Grazing Conference, 2006 (28)