Seasonal changes in the testicular size of grazing rams.

Abstract

Studies over 3 years showed that testicular volume falls during summer and autumn when forage quality and availability decline and when rams are mating. Loss in testicular size may also occur in summer in the absence of mating activity and at a greater rate than loss in live weight. The results suggest that mating and nutrition may override the influence of photoperiod on testicular size and that loss in testicular volume occurs at a time when requirement for semen is at its highest.