Genetic and Environmental Factors Affecting Size of Body and Body Parts of Turkeys: 3. The Relation of Gonad Size to Body Weight and Body Measurements at Three Different Ages

Abstract

ABSTRACT PRELIMINARY observations indicating possible genetic differences in gonad size of immature turkeys suggested further investigation of the problem. Genetic variation in gonad size has been found in studies with chickens (Jaap and Thompson, 1944; El-Ibiary and Shaffner, 1951; Hoffman, Comstock and Shaffner, 1953). According to Jaap and Thompson (1944) there is some correspondence between natal testis weight and early postnatal growth of different strains of chickens. Hoffman et al. (1953) found a significant regression of testis and ovary weight on body weight of 12-week-old chickens, although the portion of the variance accounted for by this regression was relatively small. Testis size and quantity of semen production in chickens are known to be correlated (Burrows and Titus, 1939). It is not known to what extent differences in gonad size at different ages prior to sexual maturity correspond to the differences which have been found in age at first appearance of semen . . .