A note on heritability of live-weight-for-age in Israel-Friesian dairy bull calves and its genetic correlation with milk production

Abstract

The design and evaluation of breeding programmes for live-weight-for-age (LFA) in dairy cattle requires estimates of the heritability and the additive genetic and residual components of variance for this trait, and also of its genetic correlation with milk production. A number of estimates of these parameters are available (summarised recently by Langelet, 1963; Mason, 1964; and Nichols and White, 1964). They are, however, generally based on rather limited data, on data from cows rather than bull-calves, or on data from dual purpose cattle. In this note estimates of the variance components and heritability for LFA in dairy cattle bull calves, and of the genetic correlation between bull calf LFA and milk production will be presented.