Gross Anatomy of the Intestine of the Adult Female Pekin Ducks (Anas platyrhynchos)

To our knowledge, there is no literature to define the comparative anatomical variations of the parts of the intestine in any avian species. birds. In this study, we used ten adult laying and non-laying ducks (n = 5 of each) to reveal the gross morphology and the arrangements of the intestine segments with special regard to their relation to the reproductive organs. In laying ducks, most parts of the duodenum were located on the left side of the celomic cavity meanwhile, they were in the right side in non-laying ducks. The jejunum In non-laying ducks, 14 jejunal coils were found most of which were arranged in both the right and left sides of the coelomic cavity, meanwhile, 12 coils were found most of which were located on the right side, being displaced by the enlarged reproductive organs occupying the left side. Assembly of the jejunal coils are unique in Pekins duck compared to other birds. In non-laying ducks, each cecum is a simple tube expanded at the right and directed cranially to the left where in laying it expanded on the right side, directed cranially to the left side till the middle of the gizzard, and then turned to the right again to merge returned caudally towards the left side to end by a sharp apex. Colorectum was compressed by the enlarged uterus, which occupied a narrow space of the coelomic cavity at right side. Our findings were compared with those reported in other birds and their significance was discussed