Reproductive performance of Tswana and Simmental x Tswana crosses in smallholder farms in Botswana

Abstract

Data from the Small-scale Dairy Project were analyzed to compare the reproductive performance of Simmental × Tswana crosses and purebred Tswana milking cows from smallholder farms. The effects of season (dry and wet), breed group (Tswana and Simmental crosses) and their interaction on calving interval and days open were determined. The effects of breed and year and their interaction on calving rate were determined. Correlation of monthly calving and monthly rainfall was computed. There was no difference in calving interval and days open between Tswana (576±11.3 and 296± 11.3 days) and Simmental crosses (584± 22.3 and 303± 22.3 days) cows. There were no effects of season on the calving interval and days open. There was also no breed x season interaction. Peak calving occurred between October and January (52.3%) while between May and June 15.3% of cows calved. The mean calving rate of Tswana cows (68.2%) tended to be higher than that of. Simmental crosses (62.5%) cows. There was a significant effect of year on calving rate. The implications of the results are discussed in relation to the effects of breed and season on the reproductive performance of these breeds.