Abstract INTRODUCTION IT would be of great value if males could be selected on the basis of semen quality prior to the breeding season. The thought of such a relationship is particularly intriguing in turkey management where considerable artificial insemination is practiced and where, in many instances, fertility levels are not satisfactory. Little is known regarding either changes in semen quality with advancing age or the influence of breed or cross on semen quality in turkeys. Carson et al. (1955) reported a rise in semen production from November to April or May followed by a decline to August. Conflicting reports are present in regards to sperm concentration, where Parker (1946) reported increases to March followed by a plateauing effect, but Law and Kosin (1958) found no differences from January to June. Parker (1946) reported also that motility was lower the first two months and then rose to a second plateau. The . . .