Public Health Implications Related to Spread of Pathogens in Manure From Livestock and Poultry Operations

During the 20th century, food animal agriculture grew from small operations, where livestock (cattle, sheep, and swine) and poultry (chickens and turkeys) had access to free range, to large operations where animals and poultry were concentrated and confined to feed lots or buildings. The quantity of manure produced by confinement animals in the United States has been estimated to be in excess of 61 million tons of dry matter per year (1 ), and another report states that 1.2 billion tons of manure are produced by cattle annually in the United States (US Senate Agricultural Committee, 1998). As urban developments have come closer to livestock operations, there has been increasing public concern for the impact of the latter on public health and the environment.