Estimation of genetic gain in milk yield by selection in a closed herd of dairy cattle

Abstract

1. Methods of estimating the rate of genetic gain achieved in animal improvement are discussed and criticized. 2. A theoretical method of estimation of the maximum possible genetic gain of milk yield under direct selection is presented for a closed herd of dairy cattle. The maximum possible gain is approximately 1% of the average yield. 3. The method can also be used for the estimation of genetic gain from the selection practised in an actual, herd. An estimated gain of milk yield of 0.7% per year is given for one herd.