DAIRY-HERD LIFE IN RELATION TO LINEAR TYPE TRAITS AND PRODUCTION .2. GENETIC ANALYSES FOR PEDIGREE AND NON-PEDIGREE COWS

The relation between linear type traits and survival to complete lactations 2, 3 and 4 of pedigree and non-pedigree Holstein-Friesian dairy cattle in the United Kingdom was analysed. Regressions of survival on sire transmitting abilities for type, i.e. estimates of genetic regression, were obtained for different data sets, either pedigree or non-pedigree offspring of sires whose progeny had linear type assessments made by either the Holstein Friesian Society or the Milk Marketing Board, thereby spanning different segments of the cattle population. Results were not completely consistent either over lactations or over data sets. In general, however, there was a significant positive association between survival and angularity, fore udder attachment and udder depth scores, and a negative association with chest width, rump width, and teat length. Regressions on yield were positive, while those on fat and protein content were usually negative. Survival in the herd can be predicted, although not with high accuracy, using type traits.