Bull fertility and semen quality are not correlated with dairy and production traits in Brown Swiss cattle

Summary: The genetic relationship between male reproduction and economically relevant traits is unknown. Here, we used genome-wide imputed genotypes to estimate genetic correlation between 6 estimates of male fertility and 57 dairy traits. We used allele substitution effects calculated with an additive regression approach for 11,804,781 genome-wide sequence variants. Correlations between male reproduction and other traits were small (r = -0.0681–0.0787). However, we observed correlations among various semen quality parameters and sire reproductive success (head anomalies and tail anomalies: r = 0.8380, head anomalies and motility: r = -0.7083, tail anomalies and motility: r = -0.7739, motility and volume: r = -0.1266, concentration and volume: r = -0.3503, nonreturn rate and motility: r = 0.1598, nonreturn rate and head anomalies: r = -0.1640, nonreturn rate and tail anomalies: r = -0.1580). To identify QTL responsible for the correlation among these traits, we conducted a multitrait meta-analysis; this revealed pleiotropy of a known QTL on chromosome 6 and identified a novel QTL for sperm head anomalies on chromosome 11.