Morphology of the duodenum of broiler chickens of Ross 308 cross in early postnatal ontogenesis

The article presents the results of morphometric analysis of the duodenum of broiler chickens of the cross ROSS 308 in early ontogenesis. By the end of the first day, the duodenum of chickens has all the morphological structures characteristic of this part of the small intestine. Intestinal villi in the proximal part of the intestine are predominantly finger-shaped and leaf-shaped. The height of the villi of the duodenum increases significantly during the first two weeks after withdrawal. In the proximal part it increases by 40.78%, and in the caudal part - by 43.40%. By the 2-3 day, the number of crypts, their size and the number of cells increases. By the 15th day, the number of crypts and the depth of their occurrence increases. The length of the crypts from the base of the villi to the bottom in the proximal part of the duodenum increases by 2.68 times, and in the pars caudalis - by 2.46 times. The number of goblet cells in day-old chickens in the crypts of the proximal part is significantly greater than in the pars caudalis. The width of the muscle plate of the mucous membrane in the proximal and distal areas in chickens at all age periods differs slightly. Its greatest increase is in the pars cranialis by 36.33% and in the distal by 39.59%