Abstract

Malawi would like to expand its cattle industry to meet domestic demands for meat and milk but present cattle reproduction rates are low, mainly due to poor nutrition. The objective of this project is to determine the mineral requirement of cattle grazing on Malawi's natural pastures. Researchers will determine the effects of salt, phosphorus and copper supplements on the reproductive performance of the heifers and cows grazing natural pastures; develop appropriate mineral mixtures; and, conduct a cost-benefit analysis of mineral supplementation.

Post-Project Summary

Research work was conducted at Kuti Ranch in central Malawi to test calving response in Brahman cattle grazing on natural pastures with salt (NaCl); phosphorus (P); and copper (Cu) supplements. A total of 161 cows were randomly divided into four groups and treated with four different mineral combinations. Samples of blood, soil, forages grazed by the cattle; and bone and liver biopsies were also analyzed for mineral content. There was a lack of response by experimental animals to NaCl, P, and Cu supplementation despite severe P and Cu deficiencies in forage and in the soil as well as in the animals themselves. Specifically, results from the three breeding seasons from 1985 to 1987 showed that NaCl and P supplements administered for two years did not increase the calving rate of cows. Also, supplements of NaCl, P, and Cu for all three seasons did not increase conception rates or calving rates. The only observed effect of mineral supplementation was that cows appeared in good condition.

Recipient Institution(s)