A COMPARATIVE HISTOLOGICAL STUDY ON THE SWEAT GLAND OF CATTLE (B. INDICUS) AND YAK (P. POEPHAGUS)

Yak and cattle are the species of different habitats, but are of the same genus Bos. In order to adapt to different habitats some changes may occur in cellular organizations, sweat gland morphology being one of the part of this cellular organization. The skin samples were collected from six adult nondescript male cattle and yak from five different anatomical regions viz., neck, dewlap, abdomen, back and prepuce. Sweat glands appeared tubular consisting of a secretary coil which was embedded in the dermis in cattle. In yak, the glands were saccular in the neck and dewlap regions and tubular in other regions. The sweat gland number (1729±3.44) in cattle was almost three times higher (P<0.01) than yak (615.82±3.44).Highest number of sweat gland population was found in back (1563.24±5.44) and lowest in abdomen (900.26±5.44) in both the species. Descending order of sweat gland number was detected in dewlap, neck and prepuce respectively in both the species. In cattle the sweat gland diameter was significantly (32.78±0.38 ?m) higher as compared to yak (27.68±0.38 ìm). The sweat gland number and nuclear diameter in cattle was more than yak. Acidophilic secretory granules of the glands were numerous in the supra-nuclear cytoplasm in case of cattle. These results suggest the hyper activity of sweat gland in controlling the thermo dynamics in cattle as compared to yak.