Semen Characteristics as Influenced by Selection for Divergent Growth Rate in Chickens

PROGRESS through selection has been partially responsible for the tremendous advances which have come about in the poultry industry during the last fifty years. The process of selection, however, is often conducted on a quantitative basis and problems of linkages, epistasis and other genetic properties may not only limit the rate of progress, but may also result in a reduction of other desirable traits. Genetic experiments which have been designed to study the effects of intense selection for one trait on other traits have been limited. Jones and Lamoreux (1942) studied the effect of intense selection for high and low fecundity in the female on semen characteristics in the males of these lines. Males from the high fecundity line exhibited earlier sexual maturity, larger testes weights, better semen quality and greater fertilizing capacity than the males from the low fecundity line. The authors concluded that the production of eggs and…