Histology of the Skin in an Iranian Native Breed of Sheep at Different Ages

Skin samples were collected from neonatal, young, young adult and old adult age groups. In each age group, six animals were utilized. Tissues were collected from eight regions namely belly, neck, leg, rump, flank, forearm, shoulder and hip and were fixed in 10 percent buffered formaldehyde and stained with hematoxylin-eosin and special stains. The general histological features of Bakhtiari sheep skins were similar to many other breeds stated in literature; however there were also some differences. There were no glands in the epidermis and lipid depositions on its surface. All hairs of the various skin regions surrounded by associated structures such as the sweat and sebaceous glands and arrector pili muscles located only in papillary layer of the dermis. The most common number of the secondary follicles in compound follicles was 4. The histology of various skin regions showed no significant differences by sex in all the age groups. By age increasing, all the various structures of different skin regions were larger and well organized. The size and number of secretory units of the sweat and sebaceous glands were also increased. Secretory caps of sweat glands observed only in the skin of older adult sheep.