Seasonal variations in quality, preservability and fertilizing ability of ovine spermatozoa.

The current study aimed to assess the effect of different seasons (summer, monsoon and winter) on the quality, preservability and fertilizing ability of spermatozoa in Bannur rams. The level of heat stress was significantly greater during the summer than monsoon or winter seasons. Spermatozoa concentration (×10⁶/ml) in semen was found significantly (P < 0.05) lesser during the summer (2446 ± 80) as compared to monsoon (2759 ± 56) or winter (2769 ± 56). The progressive motility (%) of spermatozoa at the 72 h post-preservation was significantly (P < 0.01) lesser during the summer (47.5 ± 2.5) than monsoon (62.5 ± 2.5) and winter (57.5 ± 2.5). Significantly (P < 0.01 or P < 0.05) lesser liveability and acrosomal integrity, but greater total morphological abnormalities of spermatozoa were recorded at all the preservation time points during the summer as compared to monsoon or winter. The cleavage rate (%) was found significantly (P < 0.01) greater during the monsoon (56.6 ± 2.24) as compared to summer (41.7 ± 1.26) and winter (41.4 ± 0.99). The results indicate a definite seasonal pattern in the quality, preservability and fertilizing ability of spermatozoa in Bannur rams, which were found superior during the monsoon. [ABSTRACT FROM AUTHOR]