Abstract

The increasing importance of the dairy herd as a source of beef has led to the initiation of breeding programs aimed at increasing rate-of-gain in dairy cattle. The overall economic value of such programs, however, will depend to a large extent on the effect of selection for rate of gain on other traits of economic importante. In Israel, A. I. sires are routinely progeny-tested for rate-of-gain as measured by the liveweight-for-age (435 days) of their bull calf offspring (LFA). Table 1 shows phenotypic correlations between the progeny tests of Israeli- Friesian dairy sires for bull calf LFA and various production characteristics of their daughters. Such correlations are usullay underestimates of the corresponding genetic correlations. Nevertheless, they do provide some preliminary notions as to the ways in which selection for rate-of-gain may affect other production characteristics in these cattle.

Moshe Soller, R. Bar-Anan

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 3, Madrid, Spain, 689–691, 1974