The limited number of goats and sheep does not supply an adequate amount of protein for the Liberian diet, but poultry farming and marketing of eggs are on the increase; there were an estimated five million chickens in 2001. Experiments in crossing West African and Brahman cattle have not yet produced breeds resistant to the tsetse fly, but the potential remains for developing good beef animals. In 2001, Liberia had an estimated 220,000 goats, 210,000 sheep, 130,000 pigs, and 36,000 cattle.