Genetic evaluation of type traits in dairy cattle

Heritability for 20 type traits was estimated from scores collected by the Vlaamse Rundveeteelt Vereniging. Firstly, scores were corrected to decrease the variance heterogeneity found between herds, breed standards and dates of classification. Next, a transformation was applied to have scores more n ormally distributed than prior to transformation. For each score, a single trait animal model was applied to estimate variance components and heritabi lity, The model included non-genetic effects for herd (*)standard(*) date o f classification, month in lactation, calving year, and interaction between age at classification and classifier. From these, herd,standard,date of cl assification and month at classification affected most type traits. Heritab ility estimates varied from 0.11 for temper ament to 0.59 for stature, and averaged 0.30 for traits measuring udder conformation. Those estimates are compared to estimates published in Holland and in Germany.