Effects of feeding maize stover and cottonseed cake on onset of puberty in Bunaji (Bos indicus) heifers.

A study was conducted to determine the influence of maize stover and cottonseed cake supplementation on age and live weight at onset of puberty in Bunaji heifers. A total of 49 pre-pubertal Bunaji heifers approximately 12 months of age were allotted randomly to one of two treatments of feed supplementation: (i) supplementation with maize stover and (ii) supplementation with cottonseed cake. The heifers were monitored for a period of 18 months for first observable oestrus or onset of puberty. The maize stover group were given maize stover (crop residue) supplementation ad libitum during the dry season; in the cottonseed cake group each heifer received 500 g of cottonseed cake per day during the dry season. The heifers supplemented with cottonseed cake attained puberty at an earlier age (23.9+/-1.2 months) than the heifers supplemented with maize stover (28.2+/-1.3 months; p<0.05). Similarly, heifers on the cottonseed cake supplementation attained puberty at a live weight of 270.5+/-3.5 kg; while the heifers on maize stover attained puberty at 237.6+/-5.8 kg (p <0.05). The cottonseed cake-supplemented heifers had higher daily gains than the maize stover-supplemented heifers. It is concluded that provision of cottonseed cake as a supplement for heifers hastened the onset of puberty when compared to the maize stover supplemented heifers. Puberty can be achieved at an early age with improved nutrition and this can in turn reduce the generation interval and thus increase the rate of genetic gain of indigenous animals. Provision of protein supplements in cattle is recommended, especially in the tropics where marked seasonality of rainfall results in extremely poor pastures and herbage and low available protein.