Comparison of occurrence and yields of daughters of progeny-test and proven bulls in artificial insemination and natural-service bulls (abstr. 1298)

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 gt42 mo after bull
  entered AI.
• NS-proven Daughters born gt8 mo after bull
  entered AI bull age ?30 mo at AI entry.

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RESULTS

• Percentage of US Holstein cows by AI status of
  sire and year of first calving

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RESULTS (cont.)

• Mean sire PTA (kg) for US Holstein cows that
  first calved during 1998 by AI status of sire

Sire PTA Sire PTA Sire PTA
AI status of sire Milk Fat Protein
AI proven, major AI 348 9 9
AI proven, minor AI 185 6 6
PT, major AI 220 10 9
PT, minor AI 142 8 6
NS proven, AI marketed 79 8 6
NS only -20 0 0
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RESULTS (cont.)

• Superiority for yield deviation (kg) of US
  Holstein cows by AI status of sire relative to
  daughters of NS bulls

Trait Milk Fat Protein
1988
AI proven, major AI 390 12 9
AI proven, minor AI 106 4 2
PT, major AI 276 12 6
PT, minor AI 188 5 4
NS proven, AI marketed 166 6 2
9
RESULTS (cont.)

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

Trait Milk Fat Protein
1998
AI proven, major AI 441 11 11
AI proven, minor AI 242 7 8
PT, major AI 242 11 8
PT, minor AI 158 6 6
NS proven, AI marketed 182 6 8
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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).

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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.

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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.