Dimensional characteristics of spermatozoa of Nili-Ravi buffalo bulls: Seasonal and climatic influences

Abstract

This study was conducted in 2 different climatic zones of Punjab Province of Pakistan, the Sahiwal and Bahawalpur divisions, simultaneously for the period of 1 year divided into seasons. Seven adult Nili-Ravi buffalo breeding bulls from each division were used. Dimensional characteristics of spermatozoa were determined. Season had a nonsignificant effect on the sperm head length in both divisions and a nonsignificant difference was also observed between bulls of the Sahiwal and Bahawalpur divisions. The buffalo bulls of both divisions exhibited significantly increased sperm head breadth in autumn, whereas a nonsignificant difference was observed between divisions. Sperm head shape values were significantly different among the seasons in both the divisions whereas they were nonsignificantly different between the two divisions. Midpiece length value was significantly higher in winter than spring in both divisions and also significantly different between the divisions. Sperm tail length was significantly increased in autumn in Sahiwal and in autumn and spring in Bahawalpur. It was significantly longer in Sahiwal than Bahawalpur. The pattern of seasonal and climatic influence on total sperm length was similar to that of sperm tail length. In conclusion, autumn and spring seasons and the climate of the Sahiwal division have additive effects on sperm dimensions, except midpiece length.