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 normally distributed than prior to transformation. For each score, a single trait animal model was applied to estimate variance components and heritability, The model included non-genetic effects for herd (*)standard(*) date of classification, month in lactation, calving year, and interaction between age at classification and classifier. From these, herd,standard,date of classification and month at classification affected most type traits. Heritability 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.