Gross, Microanatomical and Ultrastructural Studies of Interdigital Gland in Madras Red Sheep (Ovis aries)

Background: Madras Red sheep is a well-recognized meat type breed reared only on free range system to yield tasty meat. The aim of this study was to determine the gross, microanatomical and ultrastructural details of the interdigital gland in Madras Red sheep. Methods: The interdigital glands were removed immediately after slaughter and subjected for gross morphological, histological, immunohistochemical studies and ultrastructural observations. Result: The results revealed that a well-developed tobacco-pipe shaped interdigital gland was present in all the four limbs which was composed of an orifice, excretory duct, body and bent or flexure. Histologically, wall of the gland was composed of epidermis, dermis and capsule from within outward. Epidermis was made of stratified squamous keratinized epithelium. Dermis was composed of dense irregular connective tissue with sweat, sebaceous glands, arrectores pili muscle and hair follicles were embedded within. The sweat gland appeared as group of tortuous tubules under scanning electron microscope. The oily secretion of the gland helps in maintaining the healthiness of foot during movement of the animal.

Histology, lectin histochemistry and ultrastructure of interdigital gland in crossbred sheep

Histology, lectin histochemistry and ultrastructure of interdigital gland in sheep was studied using six adult cross bred sheep of either sex collected from the Meat Technology Unit, College of Veterinary and Animal Sciences, Mannuthy. The manus and pes were detached from the rest of limbs and after recording the gross observations, the interdigital glands were fixed in 10 per cent neutral buffered formalin and processed for histological examinations. Stratified squamous epithelium with a prominent keratin layer lined the lumen, similar to the skin over the dorsal surface of manus and pes. The epidermis presented mucosal folds, which projected into the lumen. The dermis contained small sebaceous glands, hair follicles of different sizes, arrector pili muscles and apocrine sweat glands. The secretory epithelium of sweat glands was lined with a simple layer of cuboidal and relatively flattened cells. The excretory ducts of these glands were lined by cuboidal cells, with darker appearance than its secretory portion. The fibrous capsule was composed of dense connective tissue with collagen, adipose cells, blood vessels and nerve fibers. Glandular secretion and the granules in the stratum granolosum of the surface squamous epithelium showed positive reaction for lectin Ulex europaeus (UEA-I). The apocrine nature of sweat glands was revealed in the ultrastructural studies by scanning electron microscope. Keywords: Interdigital gland, sheep, histology, lectin histochemistry and ultrastructure