Selecting the Young Sire to Sample in Artificial Insemination

Abstract

I should like to make three assumptions at the outset. First, we are interested primarily in milk production; secondly, we do not yet have any suitable tool for evaluating breeding values for milk production except milk production records on the individual and its relatives; and thirdly, we must accept the fact that an accurate evaluation of a dairy bull is possible only by a progeny test. If the first of these assumptions is not acceptable, we can say that the principles regarding milk production we shall discuss apply as well to other traits, but the more traits we consider, the less can any of them be improved. The second of our assumptions is obvious from the generally low genetic correlations between milk production and other traits which have been studied (fat production excluded). The third assumption needs a little more consideration. The evaluation of an untested animal can be nothing more than an appraisal of his sire and of his dam.