Biometrical, Histological and Histochemical Studies on Omasum of Gaddi Sheep

Details of the morphology of omasum in Gaddi sheep were observed by naked eye and by light microscopy. A constant and definite sequence of laminae was found. Omasal papillae on the laminae varied highly in shape, i.e. conical, rounded and finger-like. Different parameters (greater curvature, lesser curvature, weight and volume of the organ) in addition to various gross anatomical features, were studied. Average weight and volume of omasum were recorded as 126.67 gm and 73.67 ml respectively. On an average the convex greater curvature measured 15.17 ± 0.32 cm, while the concave lesser curvature measured 6.45 ± 0.13 cm. Four orders of laminae were present. The average numbers of laminae counted in I, II and III order were 11, 13 and 18 respectively. The total average number of laminae counted in I, II and III orders were 42. The core of the omasal laminae contained central muscular lamina which extended from the inner circular layer of tunica muscularis. In the omasal laminae the circular muscle was flanked on both the sides by lamina muscularis mucosa. The distinguishing feature of the omasal laminae was the presence of lamina muscularis mucosa which is not reported in rumen and reticulum in general. Histochemical reactions were mainly demonstrated in the lamina epithelialis and connective tissue core of the omasal laminae. Greater amounts of acid mucopolysaccharides were present in the omasal laminae when compared to the simple polysaccharides and lipids.