The effect of ecotype and year on the production and reproductive performance of Nguni cows in the Limpopo Province of South Africa

This study investigated the effects of Nguni cattle ecotype and year on the production and reproductive performance of cows in the Limpopo Province of South Africa. Production data for 471 calvings (142 Venda, 65 Shangaan, and 264 Pedi ecotype Nguni cows) at Mara Research Station were analysed to determine the differences between years and ecotypes in birthweight, weaning weight, days-toreconception, inter-calving period, weight of cow at breeding and at weaning, and weaning efficiency. The effects of ecotype and year on the production and reproduction parameters were analysed using the SAS® mixed models procedure. Cows of the Shangaan ecotype were the smallest in size, while the Venda ecotype was both heavy and short, and gave birth to calves with lower birthweights and higher weaning weights. Ecotype did not affect the inter-calving period and days-to-reconception, but influenced weaning efficiency and weight-related reproduction traits. Year influenced the birth and weaning weights, with years with high precipitation also having high production efficiencies. The smaller-framed Shangaan ecotype had a better weaning efficiency, days-to-reconception, and inter-calving period than the Pedi and Venda ecotypes in the year with the lowest precipitation (2011). No year effects were observed for days-to-reconception, but the inter-calving period, weaning efficiency, and weight-related reproductive traits were affected by year. Ecotype and year thus both influenced the production and reproduction traits of Nguni cattle.