THE EFFECT OF SEASONS ON THE SPERM DIMENSIONS OF BUFFALO BULLS

Summary. Dimensional characteristics and proportions of live sperma-tozoa in permanent nigrosin\p=m-\eosinpreparations from the semen samples of Murrah buffalo bulls were studied in different seasons. Between bulls, all the characteristics varied significantly. Between seasons, all the characteristics, except length of head and mid-piece, varied significantly. Environmental temperature and humidity both appeared to influence the dimensional and enumeration characteristics of the spermatozoa. The percentage of live spermatozoa decreased with increase in air tempera-ture and humidity. There is ample evidence that the dimensional characteristics of the sperma¬ tozoa of various species are under genetic control; a review on the subject has been published recently (Beatty, 1970). In tropical bulls, the seasons have been shown to influence the sperm dimensions (Mukherjee & Singh, 1966; Mishra, Singh & Roychoudhury, 1969), and the reproductive performance of buffaloes is known to be more influenced by the seasons than that of other cattle. In th