Udder type traits in genetic evaluation of clinical mastitis in Holstein cows

ZAVADILOVÁ, Ludmila, KAŠNÁ, Eva, ŠTÍPKOVÁ, Miloslava and KREJČOVÁ, Michaela. Udder type traits in genetic evaluation of clinical mastitis in Holstein cows. Chovatelské listy, 2020, vol. 2020(1), p. 18-22. ISSN .
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The aim was to evaluate the effect of selected udder type traits on the breeding value estimation for clinical mastitis, within 30 days of lactation and for the whole lactation, in Holstein cattle. On a set of 13,775 Holstein cows with 33,809 lactations, we estimated genetic parameters and breeding values for clinical mastitis traits together with udder depth, fore udder attachment, udder width and udder ligament in a multi-trait model. Thirty thousand seven hundred four animals were in the pedigree. In the first 30 days of lactation, the lactation incidence of clinical mastitis (the number of lactations in which clinical mastitis occurred) was 12%, for the whole lactation was 38%. Using the multi-trait model, there was an expected increase in the reliability of the estimation of breeding value only for the occurrence of clinical mastitis in the first 30 days of lactation. The highest increase in reliability averages was for bulls and cows with records, 4.67 and 5.34 %, respectively. Genetic correlations between clinical mastitis for whole lactation and udder depth were -30.52 %; fore udder attachment -25.75 %; udder width 33.12 %; udder ligament -13.25 %.