Effect of parity and season of calving on service period in Nili Ravi buffalo in Pakistan

The study was based on 1921 service period records of Nili Ravi buffaloes maintained at six dairy farms in Pakistan during the period 1978 to 1994. The mean service period was 237.57 +/- 4.5 days in the over all data. The highest mean service period (393.59 +/- 16.18 days) was at MDF Rawalpindi and the lowest (199.15 +/- 14.35 days) was at MDF Peshawar. The difference was significant p<0.001. Late maturing buffaloes showed significantly longer service period as compared to early maturing buffaloes. Parity and seasonal effects on Service Period were studied. There was an overall trend of reduction in the length of service period with the increase in parity. The mean (287.54 +/- 6.89 days) service period was (highest) in parity number one and lowest in parity number eight (107.95 +/- 19.72 days). The difference was highly significant. In overall data significantly lower service periods were seen in buffaloes calving in spring+winter as compared to summer+fall.