Abstract:
The data on 1491 breeding records of service period and calving interval of different grades of H. Friesian x Sahiwal 75, 62.5, 37.5, 25% and'/: (F1, F2, F3, F4) crossbred over a period of 19 years (1976-1994) were utilized. The overall average least square means and SE for service period and calving interval were137.4±6.82 and 419.78±6.04 days, respectively. Both traits were significantly (P> 0.01) influenced by year, season and parity of calving, while the year x season interaction had non-significant effect on both traits. The Spring season calvers and older cows were having shorter service period and calving interval.
