Histological Feature of the Skin at Different Regions and in Different Ages of Lori-bakhtiari Sheep

For this study, 24 Lori-Bakhtiari sheep were selected and divided into four age groups: 1-10 days, 5-8 months, 1-2 years and 3 and more years. In each age group, six animals (3 of each sex) were used. The specimens of eight different skin regions were collected. They were fixed in 10% formaldehyde solution and processed through routine paraffin embedding, cut at 5-7 μm and stained with haematoxylin and eosin, Masson trichrome, Ayoub-Shklar, Verhoeff and Foot’s method for reticulum. Histologic studies on these sections were carried out using light microscope. It was found that sex showed no significant effect on the various histological structures of all the skin regions. The thickness of total skin, epidermis, papillary layer and reticular layer of dermis varied among all the regions and was affected significantly by age and sex. The sweat glands, sebaceous glands and arrector pili muscles were found around all the hair follicles. Secretory caps were observed only in the skin of 1-2 years and 3 and more years sheep. The maximum numbers of compound hair follicles of skin in all the age groups were found to be on the shoulder, rump, flank and neck skin. The number and size of secretory units of all the skin glands had increased as age advanced.