Morphology of rectum in broiler chicken and domestic fowl: notability of retrograde peristalsis for water preservation

Abstract

ABSTRACTUsing light and electron microscopy, the rectum-coprodeum (R-C) segment of two species of chickens was examined. Six domestic fowls (Gallus domesticus) and 12 broiler chickens (ROSS 308) with the same ages were chosen for this study. Intestinal samples were sectioned with stereological procedures for quantitative studies. Sections were stained with Haematoxylin and eosin (H&E) for the light microscopic study. Transmission electron microscopy (TEM) was used for R-C segment. Villi structural variables, microvillus surface area, density and absolute surface area were considered. Results showed that the mucosa surface area decreased distally from rectum towards the coprodeum in both species. Parameters of the villi and microvilli surface area, absolute surface area and density showed decrease from proximal R-C segment towards distal. There was no significant difference in all the variables of the villi and microvilli in R-C segment (P > .05) between both species. The mean villi amplification factor in the R-C segment was low, but this factor in broiler chicken was higher (P > .05) than domestic fowl. There were no significant difference in thickness of the submucosal and muscular layers between both species (P > .05). The functional consequences in microvilli population are argued in relation to retrograde peristalsis within the rectum-coprodeum segment in birds.