Estimation of Stillbirth (Co)variance Components and Development of a Calving Ability Index

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Estimation of Stillbirth (Co)variance Components
and Development of a Calving Ability Index
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Introduction

• A national evaluation for stillbirth (SB) for
  Holstein will be implemented in August 2006.
• (Co)variance components were required.
• A calving ability index (CA) which includes SB
  and calving ease (CE) was developed.

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Stillbirth

• Reported on a three-point scale
• Scores of 2 and 3 are combined.

1 calf born alive,
2 calf born dead,
3 calf died within 48 h of parturition.
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Data

• 7 million SB records were available for Holstein
  cows calving since 1980.
• Calvings with unknown MGS were eliminated for
  VCE.
• Records with sire and MGS among the 2,600
  most-frequently appearing bulls were selected.

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Data (cont