Effectiveness of model for cow evaluation intraherd

Area of Science:

• Animal Science
• Dairy Cattle Genetics
• Quantitative Genetics

Background:

• Accurate genetic evaluations are crucial for dairy herd improvement.
• Intraherd models provide a framework for assessing individual cow performance.
• Understanding genetic trends from different relatives (sires, dams, cows) informs breeding strategies.

Purpose of the Study:

• To evaluate cow production derived from an intraherd model across six dairy breeds.
• To compare genetic trends attributed to sires, dams, and cows.
• To assess the influence of nonrandom mating on sire evaluations.

Main Methods:

• Utilized an intraherd model for cow production evaluations in six dairy breeds.
• Correlated cow evaluations within two herds against expected selection index correlations.
• Compared genetic trends derived from sire usage versus dam contributions.
• Analyzed sire evaluations against average mate evaluations to detect mating patterns.

Main Results:

• Cow evaluations within herds closely correlated with expected selection index values.
• Genetic trends from sire usage were more than double those from dam usage.
• Nonrandom mating between sires and dams was infrequent and had negligible impact on sire evaluations.

Conclusions:

• Intraherd cow evaluations are reliable predictors of genetic merit.
• Sire selection is the primary driver of genetic gain in dairy populations.
• Cow evaluations offer potential applications in inter-herd comparisons, genetic trend analysis, and predicting offspring performance.