Genetic parameters for stillbirth in Danish Holstein cows using a Bayesian threshold model.

Area of Science:

• Animal Genetics
• Reproductive Biology
• Dairy Science

Background:

• Stillbirth in dairy cattle, particularly Holstein-Friesian breeds, poses significant economic and welfare challenges.
• Understanding the genetic basis of stillbirth is crucial for developing effective breeding strategies.

Purpose of the Study:

• To infer direct and maternal genetic variation for stillbirth in first-calving Holstein cows.
• To estimate the effects of breed and heterosis on stillbirth in Danish Black and White and Holstein-Friesian cattle.

Main Methods:

• A Bayesian threshold model incorporating correlated genetic effects of sires and maternal grandsires was employed.
• Gibbs sampling was used to obtain marginal posterior distributions of effects.
• Data including and excluding twins were analyzed, with models considering breed and heterosis effects.

Main Results:

• Direct heritability for stillbirth was estimated at 0.10 (0.014), and maternal heritability at 0.13 (0.015).
• The genetic correlation between direct and maternal effects was 0.05 (0.10).
• A tendency for increased stillbirth with a higher proportion of Holstein-Friesian genetics was observed, though not statistically significant for breed or heterosis effects.

Conclusions:

• Significant genetic variation exists for stillbirth at first calving, encompassing both direct and maternal components.
• Both direct and maternal genetic effects should be considered in future dairy cattle breeding programs to reduce stillbirth rates.