Swine Manure Management

Production of pork is a major agricultural enterprise in the United States, and a majority of the production occurs in the Midwest (Ohio to Nebraska and Minnesota to Missouri) and North Carolina. Seventy-nine percent of the hogs and pigs marketed in 1987 (96.6 million head) were produced in the north-central region of the United States (Bureau of the Census 1989). Iowa has ranked first in hog inventory since 1980, and in 1987 was estimated to have 25.6 percent of the December 1 inventory of 53,795,000 hogs and pigs on farms. Inventory on farms tends to fluctuate between 50 and 70 million swine in a 4to 7-yr cycle.