Effects of season of calving and supplementary feeding on the reproductive performance of Malawi Zebu cows on smallholder farms
1992
Khonje, E.M.H. | Kamwanja, L.A. | Makhambera, T.P.E. (Bunda College of Agriculture, Lilongwe (Malawi))
Seventy-eight Malawi Zebu cows were used to determine if season of calving and supplementary feed affect reproductive performance. The study was conducted in villages surrounding Mbawa Agricultural Research Station between July 1988 and October 1990. The calving peak was during the hot dry season (August - October). The interval from calving to first oestrus was 183.4 +- 11.4 days. Correlations between cow body condition and the postpartum interval were strong and negative (r = 0.69 and r = 0.85, P0.001) for nonsupplemented and supplemented cows, respectively. The mean calving interval was 505.2 +- 17.1 days (16.8 months). Those cows which calved in the hot wet season (November - January) had a shorter calving interval. Preweaning calf mortalities shortened both the period from calving to first oestrus and the calving interval. Although most cows calve between August and October, this is a period when reproductive performance is low and therefore they would not be expected to resume cyclicity soon. From milk progesterone profiles, most supplemented cows showed regular oestrus cycles sooner than nonsupplemented ones.
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