Ileal tissue, which is at the end of the small intestine, was collected from chicks and examined for physical changes in the villi (small folds in the intestine), crypts (pockets next to the villi), and goblet cells, which produce and secrete mucin. Chicks fed cellulose or pectin had deeper crypts than chicks fed the control diet; crypts were deepest for birds fed cellulose and adequate Thr levels, and their outer intestinal muscle layer (serosa) was thicker. Chicks fed diets containing fiber had higher goblet cell counts than the birds fed the control diet, with highest levels in birds fed the pectin diet with adequate or high Thr levels.
The findings suggest that dietary Thr concentration and fiber source affect growth performance, intestinal morphology, and mucin secretion in young chicks. It also established optimal dietary Thr levels.
Having determined these levels, the researchers wanted to see if fiber and Thr in the diet could affect how chicks responded to a coccidiosis challenge. Coccidiosis is a parasitical disease of the intestinal tract caused by protozoa of the genus Eimeria maxima, which is responsible for major economic losses in the poultry industry.
"Right now, there are few advancements in coccidiosis vaccine development, so we tried to develop dietary approaches to assist the bird through a coccidiosis challenge," Dilger said. "Our hypothesis was that b
|Contact: Susan Jongeneel|
University of Illinois College of Agricultural, Consumer and Environmental Sciences