STRUCTURAL RESPONSES OF JAPANESE-QUAIL INTESTINE TO DIFFERENT DIETS

Japanese quail were fed five diets of different nutrient composition a nd the structural responses of the intestinal tract were measured. Six morphometric variables were recorded. Depending on the diet, we found drastic changes in those factors affecting surface dimensions of the mucosa epithelium and the thickness of the muscle layers of the intest inal wall. We performed a principal component analysis to describe the interrelationship among the different variables and the response of t he intestine to different diets. Two principal components were found a ccounting for surface and muscle layers respectively. Cytokinetic expe riments (TdR/BrdU double labelling of S-phase nuclei) were performed t o estimate the epithelial turnover time. We found a labelling index be tween 1.5 % and 3 % depending on the segment of the intestine. The len gth of the S-phase was found to be constant along the gut at 6.5 (+/- 2.5) hours. The epithelial turnover time, necessary to rebuild and adj ust the intestine, ranged between 10 and 17 days. We discuss evolution ary ecology perspectives as well as applied poultry aspects of the dat a.