Studies on the reproductive performance of indigenous beef cattle breeds raised on-farm in Ghana

Studies were undertaken to investigate the reproductive performance of a mixture of N'dama and West African Shorthorn (N'dama/WASH) and Sanga cattle raised under traditional management conditions on four privately owned small-holder farms. The first study involved an analysis of reproductive records and the measurement of plasma progesterone concentration to delineate the onset of various reproductive phenomena, including age at puberty and first calving, post-partum resumption of ovarian activity and other abnormal events like abortions. The second study investigated the influence of dry-season feed supplementation on reproductive performance. In study 1 the ages at first plasma progesterone rise (puberty), first mating and first calving for N'dama/WASH cattle on three farms averaged 981, 1016 and 1296 days respectively. The calving interval, calving-to-progesterone rise and calving-to-mating averaged 412, 129 and 114 days respectively. Significant differences existed among farms with Farms 1 and 2 out-performing Farm 3. The respective mean ages at first progesterone elevation, first mating and first calving for Sanga cattle (Farm 4) were 964, 990 and 1271 days while calving-to-progesterone rise, calving-to-mating and calving intervals averaged 107, 150 and 431 days. In study 2, dry-season feed supplementation generally reduced ages at puberty and first calving as well as the interval of post-partum acyclicity. (author). 18 refs, 3 figs, 9 tabs