Selection for Body Weight at Eight Weeks of Age

Comparisons of spermatozoal morphology were made between lines of chickens divergently selected for high and low juvenile body weight. Spermatozoa were classified as either normal, abnormal, or dead through the aid of vital staining. There was a significantly larger percentage of dead and abnormal spermatozoa in the high-weight line than in the low-weight line. In a second trial, when the spermatozoa were further classified into various abnormal types, the percentages of the abnormal types was consistently greater in the high-weight than in the low-weight line.