Study on the effects of season and genotypes on the reproductive performance in crossbred cattle

This study was aimed at determining the reproductive performance of various genotypes of crossbred cattle during two seasons (dry and rainy seasons) under smallholder and state farm conditions. The comparison of the fertility indices observed in various crossbred groups showed that oestrus and conception frequencies were higher in the rainy season than in the dry season. The percentages of cows showing oestrus and elevated plasma progesterone level during the post-partum period were lower in the dry season than in the rainy season. The fertility indices were significantly different in crossbred groups (P<0.05), with those in 3/4 Holstein Friesian (HF) crossbred cows being better than those in 1/2 and 7/8 HF crossbred cows. The milk yield of crossbred cattle was positively correlated with the percentage of HF blood in crosses. The milk production in the rainy season was higher than that in the dry season. The lower daily crude protein intake in the dry season depressed milk yield. There was no correlation between daily dry matter intake and milk yield in both seasons. The fertility indices and milk yield of crossbred cows which were raised under smallholder farm conditions were higher than those in animals raised under state farm conditions. The results of this study show that 3/4 HF crossbreds performed better than 1/2 of 7/8 HF crosses and that seasons affected performance. (author). 9 refs, 5 figs, 3 tabs