Abstract:
The records of reproductive traits for different parities of 147 F2 inter se H. Friesian X Sahiwal cows maintained at Livestock Production Research Institute. Bahadurnagar. Okara from 1982 to 1991 were collected for this study. Dry period. service period. calving interval, postpartum oestrus period, gestation period, services per conception. breeding efficiency and age at first calving averaged 169.3 ± 12.0 days, 177.1 12.5 days. 459.8 ± 12.6 days. 95.9 ± 8.12 dams. 282.8 ± 0.8 days. 2.2 ± 0.1, 83.88 ± 1.74 per cent and 33.46 0.51 months, respectively. The effect of parity was significant for dry period, service period. calving interval and postpartum oestrus. The effect of year of calving was non significant except for gestation period while the effect of season of calving was significant for dry period, services per conception and breeding efficiency. For age at first cah'ing the effect of year of birth was significant while the effect of season was non significant.
