Evaluating the Correlation of Seasonality on Ovarian Activity and Milk Production in Postpartum Buffaloes

The present study was conducted on healthy, lactating pleuriparous Murrah buffaloes (29), in their third to fifth parity. On basis of calving season, they were divided into two groups viz. Winter Calving Buffaloes (WCB) and Summer Calving Buffaloes (SCB). The animals were examined ultrasonographically and sampled for 63 days postpartum. During the study period, nearly 63% of WCB and 80% of SCB ovulated large follicles. The interval from calving to appearance of first corpus luteum was 31.8 and 40.8 days in winter and summer calving buffalo, respectively. SCB had non-significantly higher concentration of plasma progesterone than WCB during the postpartum period. The first rise in progesterone occurred at 21^st day postpartum in WCB and at 15^th day postpartum in SCB. The highest elevation in plasma progesterone concentration happened around 36–37^th day postpartum in both the groups. At this point, the concentration of plasma progesterone was significantly (P<0.05) high in SCB as compared to their winter counterparts (1.78 ± 0.19 ng/ml vs 0.91 ± 0.09 ng/ml). WCB produced significantly (P<0.05) higher amount of milk during first two months of lactation than SCB. Milk yield increased gradually during first three weeks of lactation in both groups. Thereafter, WCB maintained it at elevated and constant level whereas in SCB it reduced gradually after fourth week of lactation. It is concluded, that although season didn't seem to much influence the ovarian activity in both groups during early postpartum period, milk production was definitely suppressed in SCB.