Seasonal patterns of reproduction and production in Nili-Ravi buffaloes

Records of Nili-Ravi buffalo maintained at ICAR-Central Institute for Research on Buffaloes, sub-campus Nabha for the period 2009–2018, were analysed with the aim to study the effect of season on various reproductive and productive parameters. Seasons were categorized as follows: winter –Nov. to Feb.; summer – Mar. to Jun.; and rainy – Jul. to Oct. The average temperature ranged from as high as 32.3°C in summer to as low as 18.4°C in winter. The average humidity ranged from as low as 28.2% in summer to as high as 52.8% in rainy season. Data of 4,203 estruses during this period revealed significant effect on estrus expression with lower expression in summer, and highest during winter. A significant reduction in estrus detection efficiency during summer and rainy seasons as compared to winter was recorded. The conception rate was significantly higher during winter as compared to summer and rainy season. During this period, 1,398 calvings were recorded. It was observed that buffaloes that calved in summer tended to have highest calving to first service interval as well as service period (135 and 167 d, respectively) and lowest in rainy season (78 and 114 d, respectively). The wet and herd averages were significantly higher in winter as compared to summer and rainy. Animals that calved in rainy season had significantly lower lactation length (299±13 d) as compared to summer (373±13 d) and winter (320±17 d). It may be concluded that high temperature and humidity during summer and rainy season exert negative effect on reproductive and productive performance in Nili-Ravi buffaloes.