United States Department of Agriculture Herdmate Comparison sire summaries were studied over time for bulls originally sampled under limited and multiherd conditions.An independent summary free of daughter information included in the initial evaluation served as the standard for comparison.Initial summaries on limited-herd bulls were not as reliable as summaries on multiherd bulls in predicting herdmate deviation in the independent summary.The correlation between summaries for multiherd bulls was .66compared to .53 for limited-herd bulls.When the initial summary was corrected for pedigree information, correlations increased for both groups to .70 for multiherd and .60 for limited-herd bulls.The change in Predicted Difference per year for the two groups indicated that limited-herd bulls were overevaluated by 119 kg on their initial summaries compared to multiherd bulls.Correcting for pedigree information reduced the overestimation to 69 kg.The Herdmate Comparison produced estimates of sire merit for fat of nearly equal accuracy for both groups.Results support evidence of benefits from careful pedigree selection for production traits in bulls used under limited and multiherd conditions.
No takes yet. Share an insight, caveat, or question.
Cassell et al. (1976) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: