Seasonal Variation in Semen Production in Domestic Fowls

Abstract

INTRODUCTION OBSERVATIONS by a number of investigators including Pearl and Surface (1911) and Whetham (1933) show that egg production in the hen is influenced by season. Highest egg production tends to be correlated with increasing length of day. Because of the similarity of the hormonic mechanisms governing egg production in the female and spermatozoa formation in the male, it was thought probable that semen production in the domestic cock likewise is related to length of day. Results of previous studies (Parker, McKenzie, and Kempster, 1942) showed that, when semen was intercepted in a semen collector during mating trials, male fowls ejaculated the greatest number of sperms during the spring months. However, since the influence of libido was not eliminated, these results were not necessarily indicative of the rate of spermatozoa formation. The following experiment was conducted to determine whether there are measurable seasonal differences in semen production in the cock.