Effect of dietary selenium on small intestine villus integrity in reovirus-challenged broilers

Enteric Avian Reoviruses (ARV), associated with malabsorption, lower weight gains and increased mortality in broiler chickens, target enterocytes on intestinal villi causing villus dysfunction and decreased digestion and absorption of nutrients. This investigation examined whether enteric ARV infection with or without dietary Selenium (Se) (organic or inorganic) affected small intestinal integrity. Eggs from Cobb 500® broiler breeders fed low-Se semi-purified diets with no supplemental Se, or with 0.3 ppm supplemental Se provided by organic Se (Se-yeast, Sel-Plex®, Alltech, Inc., Nicholasville, KY, USA), or by sodium selenite, were hatched and the chicks were subjected to the same three dietary Se treatments as their respective parents. At hatch, 30 chicks per dietary Se treatment were placed into either control or ARV-infected groups in heated batteries in separate isolation rooms. ARV-infected chickens were given orally ARV-CU98 (10^4.2 pfu/chick in 0.5 mL) and control chickens received medium only. Intestinal tracts from 21-d-old chickens were examined histomorphometrically revealing longer and more narrowvilli, greater surface perimeter, more shallow crypt depth and significantly greater height to crypt depth (H:D) ratios in Sel-Plex-fed control and infected birds, compared with respective values from birds fed no supplemental Se or sodium selenite. The differences in H:D ratios between Se treatments indicates that Sel-Plex is more effective than either no Se or sodium selenite supplementation in protecting the integrity of the small intestine villi.