LIVESTOCK BREEDS AND THEIR CONSERVATION - A GLOBAL OVERVIEW

Of the 3831 breeds or breed varieties of ass, water buffalo, cattle, g oat, horse, pig, and sheep believed to exist or to have existed this c entury, 618 (16%) are estimated to have become extinct of the 3213 exi sting breeds, 475 (15%) are defined as rare. Worldwide, the horse is t he species most differentiated into breeds and the water buffalo the l east. Breed biodiversity varies markedly between continents, being gre atest in Europe and least in South and Central America and Oceania. In the countries of the Old World, numbers of breeds are correlated with human population and with land area, implying that conditions favorin g growth in human population also favor diversification of breeds Peri pheral and remote countries have the highest ratios of breeds per mill ion people, implying that remoteness can also promote diversification. Breed extinctions have been most thoroughly documented in Europe and the former U.S.S.R., where the richest countries have lost the highest proportions of their breeds, implying that agricultural development i s hostile to breed diversity. Data are particularly lacking from the d eveloping world, and the Global Data Bank for Domestic Livestock of th e Food & Agriculture Organization of the United Nations has been set u p to collate census and production information.