Cattle, rainfall, and tsetse in Africa

Increased population pressure has led to attempts to reclaim some to the ten million square miles of Africa in which tsetse fly occur. The paper traces the occurrence of tsetse fly, and its impact on cattle. In tsetse free areas, cattle biomass increases with rainfall, but in countries partially infested with tsetse, no clear relationship with rainfall is shown, and countries with high incidence of tsetse have low cattle biomasses whatever the rainfall. The author concludes that if tsetse fly were to be eradicated, this could lead to an increase in the biomass of cattle in these regions. He cautions that this could entail the degradation of much of the land as has occurred in tsetse free areas, and then the decline in productivity; he proposes that research into optimum carrying capacity should be carried out in order to maximize production. He asserts that optimum carrying capacity predictions derived from meteorological statistics have some validity, and would be useful for desirable stocking levels for economic assessment of tsetse eradication programs, and for livestock development projects generally. -b/m