The Relationship between Distiller’s Dried Grains with Solubles (ddgs) and Ileitis in Swine

Ileitis, also known as porcine proliferative enteropathy, is an enteric disease of the lower small intestine and occasionally large intestine that can decrease feed intake, reduce growth performance, and increase mortality in swine. The disease is caused by a gram negative microaerophil bacteria called Lawsonia intracellularis, an intracellular parasite of the enterocytes of the intestine (Dufresne, 1999). Lawsonia intracellularis infects immature epithelial cells located in the crypts of the intestine, keeping them from maturing and causing them to multiply without leaving the intestine. This results in cellular proliferation and thickening of the infected intestine (primarily ileum and ileocaecal junction), and can result in necrosis, ulceration, and hemorrhaging of the epithelial surface (see Figure 1). Tests using the National Animal Health Monitoring System (NAHMS) serum bank indicate that Lawsonia intracellularis is present in 96% of all U.S. swine herds (Bane et al., 1997). This disease has been estimated to cost the U.S. pork industry $20 million annually, based on calculations utilizing NAHMS data, and as much as $8.50 per pig in an infected herd.