Selection Differentials from National Holstein Bull Progeny Test

Selection Differentials from National Holstein Bull Progeny Test Programs Estimated from International Data R. L. Powell*, H. D. Norman and A. H. Sanders Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD rpowell@aipl. arsusda. gov 2002

Characteristics of Ideal Progeny Test Program • High pedigree merit • Large number of bulls • Rapid and accurate evaluation - Large number of daughters/herds • Intensive culling ADSA 2002 (2) R. L. Powell 2002

Objective • Document characteristics of national progeny test (PT) programs - Age of bulls at decision - Percent of bulls retained - Standardized selection differentials (selection intensities) • Compare PT strategies of different countries ADSA 2002 (3) R. L. Powell 2002

Comparison Considerations • Many factors affect PT program quality • Complex relations between factors A country may have higher pedigree requirement, but return more bulls to service and have a lower selection differential. ADSA 2002 (4) R. L. Powell 2002

Data • Holstein Interbull evaluations • PT decisions February 1996 - 1998 • Eleven countries with at least 125 PT bulls over this period ADSA 2002 (5) R. L. Powell 2002

Assumptions • PT decision made on second evaluation provided by Interbull • Country of PT was country with most daughters in decision evaluation • Returned to service if 200 daughters added in country of PT from evaluations 2. 5 to 4. 5 years after PT decision ADSA 2002 (6) R. L. Powell 2002

Numbers of Bulls Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (7) Evaluations 1 5 5 3 5 5 2 5 5 Bulls Bull Age (mo) 153 1108 888 1547 1855 145 735 1055 266 223 3616 69 69 66 77 70 72 73 66 67 75 66 R. L. Powell 2002

Numbers of Bulls Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (8) Evaluations 1 5 5 3 5 5 2 5 5 Bulls Bull Age (mo) 153 1108 888 1547 1855 145 735 1055 266 223 3616 69 69 66 77 70 72 73 66 67 75 66 R. L. Powell 2002

Numbers of Bulls Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (9) Evaluations 1 5 5 3 5 5 2 5 5 Bulls Bull Age (mo) 153 1108 888 1547 1855 145 735 1055 266 223 3616 69 69 66 77 70 72 73 66 67 75 66 R. L. Powell 2002

Herds, Daughters, and Reliabilities Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (10) Herds Daughters REL (%) 42 61 79 75 75 38 54 114 39 76 70 91 79 104 58 70 125 103 147 54 80 86 88 87 89 84 84 92 89 91 80 R. L. Powell 2002

Herds, Daughters, and Reliabilities Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (11) Herds Daughters REL (%) 42 61 79 75 75 38 54 114 39 76 70 91 79 104 58 70 125 103 147 54 80 86 88 87 89 84 84 92 89 91 80 R. L. Powell 2002

Herds, Daughters, and Reliabilities Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (12) Herds Daughters REL (%) 42 61 79 75 75 38 54 114 39 76 70 91 79 104 58 70 125 103 147 54 80 86 88 87 89 84 84 92 89 91 80 R. L. Powell 2002

Selection Intensities Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (13) Selection Intensities Return to Service (%) Milk Fat Protein 3. 9 5. 4 4. 4 8. 5 15. 6 3. 4 6. 8 5. 1 10. 2 4. 9 7. 7 1. 03 1. 01 1. 05 0. 89 0. 81 1. 24 0. 88 0. 70 0. 73 1. 26 0. 86 1. 13 0. 69 0. 85 0. 78 0. 33 0. 79 1. 03 1. 02 1. 08 0. 62 1. 32 1. 07 1. 25 1. 26 0. 96 1. 27 1. 11 1. 14 1. 24 1. 64 0. 94 R. L. Powell 2002

Selection Intensities Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (14) Selection Intensities Return to Service (%) Milk Fat Protein 3. 9 5. 4 4. 4 8. 5 15. 6 3. 4 6. 8 5. 1 10. 2 4. 9 7. 7 1. 03 1. 01 1. 05 0. 89 0. 81 1. 24 0. 88 0. 70 0. 73 1. 26 0. 86 1. 13 0. 69 0. 85 0. 78 0. 33 0. 79 1. 03 1. 02 1. 08 0. 62 1. 32 1. 07 1. 25 1. 26 0. 96 1. 27 1. 11 1. 14 1. 24 1. 64 0. 94 R. L. Powell 2002

Selection Intensities Country Australia Canada Denmark France Germany Great Britain Italy Netherlands New Zealand Sweden United States ADSA 2002 (15) Selection Intensities Return to Service (%) Milk Fat Protein 3. 9 5. 4 4. 4 8. 5 15. 6 3. 4 6. 8 5. 1 10. 2 4. 9 7. 7 1. 03 1. 01 1. 05 0. 89 0. 81 1. 24 0. 88 0. 70 0. 73 1. 26 0. 86 1. 13 0. 69 0. 85 0. 78 0. 33 0. 79 1. 03 1. 02 1. 08 0. 62 1. 32 1. 07 1. 25 1. 26 0. 96 1. 27 1. 11 1. 14 1. 24 1. 64 0. 94 R. L. Powell 2002

Conclusions • Reliability at PT decision time: 80 -92% • Mean bull age by country: 66 -77 months • PT bulls return to service by country: 3. 4 -15. 6% (Mean 6. 9) • Selection intensities: . 33 -1. 64 (Tended ~1) • Highest selection intensities were for protein in all 11 countries ADSA 2002 (16) R. L. Powell 2002