Histomorphometrical and histochemical studies on the omasum of adult Bakerwali goat, non-descript goats and non-descript sheep of Jammu region: A comparative adaptational perspective.

BACKGROUND: The omasum absorb water, electrolytes, volatile fatty acids by regulating the flow of digesta from the reticulum to the abomasum. In the Jammu region, small ruminants are raised under various agro-climatic conditions. Sheep mainly graze, while goats primarily browse. Such differences in feeding habits influences anatomy of digestive tract, especially the omasum. Studying omasum structure helps explain differences in digestive efficiency, nutrient utilization, and environmental adaptation among these species.

AIMS: The present study aimed to compare anatomy of omasum in Bakerwali goats, non-descript goats and non-descript sheep and help develop breed-specific management strategies.

METHODS: Gross morphological, biometrical, histomorphological, micrometrical and histochemical studies were undertaken. Samples were fixed and processed for standard histological procedures and stained with various stains for histological and micrometrical observations.

RESULTS: Omasum was laterally compressed oval to bean-shaped sac in all the three species. Internally, omasum was characterized by omasal laminae. The 4th order laminae were prominent in adult non-descript sheep. Lateral surface of the 1st order laminae presented ridges running parallel to the free concave border in adult non-descript sheep. Total empty weight, capacity and number of omasal laminae was significantly highest in non-descript sheep. Histologically, omasal laminae were thickest in non-descript sheep and thinnest in non-descript goats.

CONCLUSION: The present research extends the depth of the knowledge regarding anatomy of omasum. The anatomical differences in the omasum between browsers and grazers can be correlated to their digestive physiology.