Effect of Seasonal Mating on Calves’ Birth Weights of Mpwapwa Cattle Breed and its Crosses Produced at Tanzania Livestock Research Institute

Abstract

Aims: A study was conducted to assess how seasonal mating could influence calf birth weight in cattle among Mpwapwa breed and its four crossbreeds reared at Tanzania Livestock Research Institute (TALIRI) farm. Study Design: This study used farm data collected at TALIRI, Mpwapwa centre. A total of 585 calves of Mpwapwa cattle breed and its four different crosses, born between 2018 and 2023 were included in the study. Among those, 395 were born during the dry season (June to November) while 190 were born during the rainy season (December to May). Methodology: To assess for significance of differences in mean birth weights between seasons and crossbreeds, a two – way ANOVA with interaction was performed, followed by univariate pairwise comparisons with Bonferroni correction while pairwise differences between crossbreeds were assessed using an independent samples t – test. Results: The results showed that, mean birth weights differed between seasons (F=4.88, P=.03) and between calf crossbreeds (F=17.33, P<.001). The mean birth weight of calves born during the rainy season (24.4kg) was higher compared to that of calves born during the dry season (23.4kg) (P=.04). Overall, Vianze calves had highest mean birth weight (26.6kg, n = 64), followed by Kikombo calves (25.7kg, n = 61), Matondwe (24.5kg, n = 35) and Chibamba calves (24.4 kg, n = 81). Mpwapwa calves had the lowest mean birth weight (22.6kg, n = 344). Conclusion: These findings demonstrate the importance of strategic feeding especially of pregnant cattle in optimizing subsequent mean calf birth weights. Feeding the pregnant cattle with maize leftovers and hay resulted to higher birth weights. Also, the role of cattle crossbreeding programs in improving calf birth weights has been demonstrated.