Abstract

Progeny testing of beef animals generally follows one of two methods: either to keep progeny together under closely controlled husbandry at one centre, or to place progeny at different farms and compare their performance with those of their contemporaries. Theoretically, the latter method is advantageous because it enables bulls to be tested over a large range of environments. Practically, however, it is difficult to control, and factors such as the effect of season and fluctuation in management within farms cannot satisfactorily be taken into account. Keeping progeny together in one environment is preferable from the point of view that the data collected are reliable, but any interactions between genetics and systems of rearing and management cannot be taken into account. Thus there is no guarantee that the «superior bulls» selected on the basis of this type of progeny test will necessarily produce off-spring which will grow well when conditions of feeding and husbandry become less favourable.

G. J Rowlands

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 3, Madrid, Spain, 783–787, 1974