A multi-trait genetic analysis of protein yield, udder health, and fertility in first lactation Danish Holstein, Danish Red, and Danish Jersey using an animal model

Abstract

The objective of this study was to estimate genetic correlations between yield and functional traits in Danish dairy cattle. For each breed information on about 250,000 first lactation cows were included in the analysis. The models used were similar to those used in the routine genetic evaluation. Heritabilities of protein yield (PY), somatic cell score (SCS), clinical mastitis (CM), and the fertility traits were 0.34, 0.14–0.15, 0.03–0.05, and 0.02–0.04, respectively (range describing variation between breeds). The genetic correlations between PY and the udder health traits and PY and the fertility traits were all positive and unfavorable. The genetic correlation between CM and SCS was as expected high, as were the correlations between the fertility traits. The genetic correlations between udder health and fertility traits were moderate to low and favorable. These results emphasize the importance of continuing including functional traits in the breeding goal.