RESULTS (cont.)

1
Abstr. M11
Contribution of inbreeding and recessive defects
to early embryo loss P.M. VanRaden and R.H.
Miller Animal Improvement Programs Laboratory,
Agricultural Research Service, USDA, Beltsville,
MD 20705-2350

• INTRODUCTION
• Reproductive traits adversely affected by
  inbreeding because of large nonadditive genetic
  variance
• Recent interest in crossbreeding because of
  declining female reproductive efficiency
• Recessive genetic defects that cause embryonic
  death expressed as complete dominance and add to
  fraction of nonadditive genetic variance
• Complex vertebral malformation (CVM)
• Swedish Holstein carrier bulls had lower 168-d
  nonreturn rates no difference for 28- and 56-d
  nonreturn rates
• (Persson, 2003, Undergraduate Thesis, Swedish
  Agric. Univ., Uppsala)
• Deficiency of uridine monophosphate synthase
  (DUMPS)
• Probability that mates will be carriers for same
  genetic defect increased by inbreeding

• METHODS
• Model included herd-year-season, cow parity, cow
  sire, service sire, regression on inbreeding, and
  interaction of service sire and cow sire
• Service sire effects constant and uncorrelated
  across time
• Additive relationship matrix for cow sire
• Dominance relationship matrix for interaction
• Additive additive effects not included
• Variance estimation (Hoeschele, 1991, J. Dairy
  Sci. 741743)
• REML for main effects and data adjusted
• Tilde-hat REML approximation for interaction
  effect
• Analysis to determine if bull CVM and DUMPS
  status explained variation in interaction effect

• RESULTS (cont.)
• Deviation in NR70 for interactions of service
  sire with cow sire (gt25 first services/combination
  )

Service sire Service sire Service sire Cow sire Cow sire NR70 deviation Embryo inbreeding () Services (no.)
Name CVM status CVM status Name CVM status NR70 deviation Embryo inbreeding () Services (no.)
Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects Worst 5 interactions inbreeding effects
United Nick Norrielake Cleitus Luke 0.0356 4.7 124
Maizefield Bellwood Maizefield Bellwood 0.0344 25.0 33
Stardell Valiant Winken To-Mar Blackstar 0.0320 0.0 66
Schutzs Brass Bell GLC Jordache 0.0319 0.0 217
Stardell Valiant Winken Robthom Integrity 0.0313 0.7 251
Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects Best 5 interactions inbreeding effects
Paradise-R Cleitus Mathie Regancrest Mascot Dello 0.0288 0.2 199
Paradise-R Roebuck MJR Blackstar Emory 0.0278 0.0 502
Paradise-R Cleitus Mathie Shen-Val NV LM Formation 0.0273 1.6 208
Paradise-R Cleitus Mathie Scil Buckeye 0.0270 0.0 227
Coyne Farms Bonanza Howcrest Aristides 0.0270 3.1 189
Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects) Worst 5 interactions (excluding inbreeding effects)
Stardell Valiant Winken Stardell Valiant Winken To-Mar Blackstar 0.0320 0.0 66
Schutzs Brass Bell Schutzs Brass Bell GLC Jordache 0.0319 0.0 217
United Nick United Nick Norrielake Cleitus Luke 0.0310 4.7 124
Stardell Valiant Winken Stardell Valiant Winken Robthom Integrity 0.0305 0.8 251
Schutzs Brass Bell Schutzs Brass Bell Pen-Col Duster 0.0283 0.0 217
Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects) Best 5 interactions (excluding inbreeding effects)
Coyne Farms Bonanza Coyne Farms Bonanza Howcrest Aristides 0.0300 3.1 189
Paradise-R Cleitus Mathie Paradise-R Cleitus Mathie Regancrest Mascot Dello 0.0290 0.2 199
Paradise-R Cleitus Mathie Paradise-R Cleitus Mathie Shen-Val NV LM Formation 0.0288 1.6 208
Shen-Val NV LM Fashion Shen-Val NV LM Fashion The Choice of Mark Adam 0.0283 4.0 121
Paradise-R Roebuck Paradise-R Roebuck MJR Blackstar Emory 0.0278 0.0 502
Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested () Negative (), positive (), and not tested ()

• RESULTS
• Regression of NR70 on inbreeding of embryo was
• 0.096 per 1 increase in inbreeding, which
  could be explained by fatal defects in gt20 of
  embryos
• 348 bulls mated to own daughters
• Variation
• Service sire 0.36
• Cow sire 0.24 (heritability of 1.0)
• Interaction 0.18 (dominance variance of 2.8)
• Interaction of service sire with cow sire
• Total of 369,017 bull combinations
• Mean of 6 records per bull combination
• 50 bull pairs withgt500 records (maximum of 2077)
  and reliability of gt50
• Estimates (compared to mean NR70 of 56)
• Including inbreeding effect 3.6 to 2.9
• Excluding inbreeding effect 3.2 to 3.5
• CVM/DUMPS status
• 2195 combinations included 2 known CVM carriers
• No indication that CVM or DUMPS status explained
  variation in NR70

• OBJECTIVES
• Using 70-d nonreturn rate (NR70) as a measure of
  reproduction, determine
• Magnitude of nonadditive genetic variance
• Effects of inbreeding
• Extent that recessive genetic defects contribute
  to nonadditive variance

• DATA
• NR70 based on 1.74 million first AI services of
  US Holsteins from 1995 through 2000
• All dairy records processing centers represented
  except DHI-Provo
• 1,251 bulls included as cow sire or service sire
• gt100 daughters for cow sires
• gt500 first services for service sires
• Genotyping results to determine bull CVM and
  DUMPS carrier status

• DATA
• NR70 based on 1.74 million first AI services of
  US Holsteins from 1995 through 2000
• All dairy records processing centers represented
  except DHI-Provo
• 1,251 bulls included as cow sire or service sire
• gt100 daughters for cow sires
• gt500 first services for service sires
• Genotyping results to determine bull CVM and
  DUMPS carrier status

• CONCLUSIONS
• Substantial negative impact from increased embryo
  inbreeding on conception and 70-d survival after
  insemination
• Substantial dominance variance for NR70 (nearly 3
  times larger than additive variance)
• Variation in NR70 not related to status of
  service sire or cow sire for CVM (losses later in
  gestation) or DUMPS (few carrier bulls)
• Investigation of embryo loss later in gestation
  needed to determine impact of bull CVM status