The Role Of Minerals In The Growth And Viability Of Bunaji Cattle Raised Under Traditional Management In Central Nigeria.

Abstract

About 400 Bunaji cattle from 12 herds at three sites namely, Kurmin Biri, Madauchi and Ganawuri were used to study the productivity of cattle fed mineral supplements under village conditions. Two herds at each site were allocated at random to each treatment. Mineral blocks containing 11% P and local salt licks containing 96% NaCI which served as control were fed. Supplementation lasted three years. Mineral blocks were put out daily in the Kraals and taken in during rains and when the animals went grazing. Births and disposals were recorded. Animals were weighed monthly using portable barlo electronic scales. Animals grazed natural pasture and crop residues after harvest. Data were analysed using general linear models (GLM) procedure of SAS, Analysis were done for birth weights up to 18 months. Models used for analysis involved the fixed effects of location, herds nested within location, year and season of calving, parity, age of dam and sex of calf. The results showed that birth weights were significantly influenced by location (P<0.05), year of birth (P<0.05) and mineral supplementation (P<0.05). The birth weights were 22.4±0.53, 21.1± 0.42 and 18.2±0.40 kg in Ganawuri, Kurmin Biri and Madauchi respectively. Calves born in 1988 were significantly heavier than those born in 1989 and 1990 and weighed 21.1±0.47, 19.8±0.39 and 20.8±0.48 kg in 1988, 1989 and 1990 respectively. The mineral supplemented calves weighed 21.1±0.38 and 19.9±0.36 kg for phosphate and salt respectively. Using weight as a covariate, it was shown that the growth rate of P supplemented group was significantly higher than the control group (P<0.05) so that at 18 months the mineral group weighed 165 kg, an improvement of 22%. Calving interval was influenced by location (P<0.05), year of calving (P<0.01) but not significantly by treatment (P>0.05). Calving intervals were 530±62.9 and 503±54.8 days for mineral and salt respectively. Cumulative mortality percentage of calves to 9 and 12 months were not significantly affected by mineral supplementation (P>0.05). These were 11.1±5.00 and 13.4±5.31 and 17.4±5.06 and 24.0±5.43 for mineral and salt respectively. It is concluded that the provision of P-rich mineral blocks to agropastoral herds at strategic periods can improve the productivity of Bunaji cattle.