Effect of heat stress on physico-morphological characteristics and sperm functions in Murrah buffalo semen

Abstract

The objective of the present study was to study the effect of heat stress induced by summer in relation to winter on physico-morphological characteristics and sperm functions in Murrah buffaloes semen. The study was conducted at the Artificial Breeding Research Centre, NDRI, Karnal. Meteorological data were recorded during summer and winter, and THI was calculated. Six adult Murrah buffaloes were selected and two sample from each buffalo were collected every month by AV method. A total of 84 ejaculates were collected and assessed for various seminal attributes in summer and winter. Seminal parameters assessed included volume, pH, mass motility, progressive motility, livability, abnormality, membrane integrity, protamine deficiency and apoptosis assessment in fresh semen. Results of THI (80.92) during summer revealed moderate heat stress condition. There was no significant effect of heat stress on ejaculate volume and pH. Sperm motility was significantly higher during winter than summer. Similarly, significantly lower sperm livability and membrane integrity were observed during summer compared to winter. Abnormal and protamine deficient sperm per cent was significantly higher during summer. Lower apoptotic sperm per cent was found in winter. It can be concluded that seasonal variations had a significant effect on semen quality of Murrah buffalo. Heat stress induced by summer (hot humid) season had the most adverse effect on various physico-morphological and sperm functions in Murrah buffalo semen.