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H.D. Norman,  R.L. Powell, and J.S. Wright

Comparison of occurrence and yields of daughters of progeny-test and proven bulls in artificial insemination and natural-service bulls (abstr. 1298). H.D. Norman,  R.L. Powell, and J.S. Wright

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H.D. Norman,  R.L. Powell, and J.S. Wright

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  1. Comparison of occurrence and yields of daughters of progeny-test and proven bulls in artificial insemination and natural-service bulls(abstr. 1298) H.D. Norman, R.L. Powell,and J.S. Wright Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705-2350

  2. INTRODUCTION Genetic comparison of natural-service (NS), progeny-test (PT), and AI-proven bulls available at the same time depends partly on selection intensity. Previous studies have indicated that PT bulls had superior genetic merit to AI-proven bulls for yield, but that advantage may be decreasing. Knowledge of current genetic merit expected from the use of PT, AI-proven, and NS bulls would benefit producers in making economic decisions.

  3. OBJECTIVES Characterize AI contribution to US Holstein population across time. Compare genetic merit of PT, AI-proven, and NS bulls available at the same time.

  4. DATA Holstein sire PTA and cow yield deviations for milk, fat, and protein available from USDA national dairy database for breedings since 1959. Only first-parity records usable for genetic evaluations included. Records grouped by AI status of cow's sire: AI proven, major AI organization. AI proven, minor AI organization. PT, major AI organization. PT, minor AI organization. NS proven, AI marketed. NS only.

  5. DEFINITIONS AI organizations: Major: Located in US and has a National Association of Animal Breeders (NAAB) controller number between 1 and 222. Minor: Markets but does not process semen. AI status: PT: Daughters born 8-42 mo after bull entered AI. AI-proven: Daughters born >42 mo after bull entered AI. NS-proven: Daughters born >8 mo after bull entered AI; bull age 30 mo at AI entry.

  6. RESULTS Percentage of US Holstein cows by AI status of sire and year of first calving:

  7. RESULTS (cont.) Mean sire PTA (kg) for US Holstein cows that first calved during 1998 by AI status of sire:

  8. RESULTS (cont.) Superiority for yield deviation (kg) of US Holstein cows by AI status of sire relative to daughters of NS bulls:

  9. RESULTS (cont.) Superiority for yield deviation (kg) of US Holstein cows by AI status of sire relative to daughters of NS bulls: (cont.)

  10. CONCLUSIONS Percentage of cows sired by AI-proven bulls from major AI organizations was relatively constant (64% for 1988, 63% for 1998). Percentage of cows sired by AI-proven bulls from minor AI organizations increased (2 to 12%). Percentage of cows sired by PT bulls increased (10 to 17%). Percentage of cows sired by NS-proven bulls marketed through AI decreased (15 to 2%). Percentage of cows sired by NS bulls decreased (9 to 6%).

  11. CONCLUSIONS (cont.) AI-proven Holstein bulls from major AI organizations were genetically superior for milk yield: 128 to 206 kg compared with PT bulls. 368 kg compared with NS bulls. and nearly equal or superior for fat and protein: -1 to 3 kg compared with PT bulls. 9 kg compared with NS bulls. First-parity daughters of NS Holstein bulls were inferior for milk, fat, and protein yields compared with first-parity daughters of other Holstein bulls during 1988 and 1998.

  12. CONCLUSIONS (cont.) First-parity daughters of AI-proven Holstein bulls from major AI organizations outproduced first-parity daughters of NS Holstein bulls in 1998 by: 441 kg of milk. 11 kg of fat. 11 kg protein. Results represent only first-parity US Holstein records usable for genetic evaluations and may not characterize the entire US dairy population. More extensive use of AI could increase annual income of US dairy producers by approximately $96/cow.

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