Abstract
Data on reproductive performance of zebu and Friesian x zebu crossbred cows reared under small-scale dairy farms were analysed and the effects of genotype, parity, body condition score (BCS), season, and year of calving were examined for a total of 246 calvings. Uterine involution was completed earlier in zebu (23.8 ± 1.2 days) than in crossbred (31.4 ± 1.3 days) and in primiparous (25.4 ± 2.0) than in pluriparous (29.7 ± 0.8 days) cows (P < 0.05). Body condition score, season, and year of calving had no effect on uterine involution (P > 0.05). The interval from calving to resumption of ovarian activity was influenced (P < 0.05) by BCS at calving but not by parity, season, and year of calving. The interval between calving and conception was influenced by genotype (P < 0.05) and was earlier in crossbred (148.4 ± 11.8 days) than in zebu (183.2 ± 11.7 days). The overall mean for calving interval was 509.7 days and there was an effect of year of calving (P < 0.05). It was concluded that BCS and genotype affected the duration from calving to resumption of ovarian activity and conception, respectively.
