Histological indicators of sheep skin of different directions of productivity

Abstract

The purpose of the research was to study the histological indicators of sheep skin of different directions of productivity and to identify the effectiveness of using sheep of foreign breeds on the breeding stock of domestic fine-wooled sheep of the meat-wool direction of productivity. An analysis of histological indicators of sheep skin in diff erent areas of productivity, including the histostructure of the skin of sheep breeds of foreign selection such as Poll Dorset, Charolais and Ile de France, sheep breeds of domestic selection Stavropol, Manych merino and Dzhalginsky merino has been presented in the article. The study of the mechanism of growth and development of wool fi bers is one of the main tasks of increasing the quantity and improving the quality of wool. In studying the morphology of the skin, it is important to establish the breed and age features of the structure of the root, glandular systems, collagen structures that ensure the quality of sheep skin and wool fi bers. Thus, in sheep of Poll Dorset breed the total skin thickness was 10,3 and 3,6 % higher than in Charolais and Ile-de-France animals, respectively. At the same time, the thickness of the epidermis was almost 1,0 % of the total thickness of the skin, while the pilar layer averaged 61,8 %, the reticular layer 37,23 %, which is consistent with the breed parameters. The biggest density of follicles was observed in sheep of Ile-de-France and Charolais breeds. The superiority over animals of Poll Dorset breed was 17,5 and 10,0 %, respectively. By the ratio of secondary follicles/primary follicles animals of Poll Dorset and Ile-de-France breeds had superiority over Charolais breed by an average of 12,4 and 11,2 %. Sheep of domestic selection had an advantage in skin thickness in animals of Manych merino breed. They surpassed their herdmates of Stavropol breed by 5,2 % and Dzhalginsky merino breed by 11,2 %. In terms of the total density of follicles, animals of Stavropol breed had a slight advantage. The animals of Manych merino breed were 3,2 % inferior to them and Dzhalginsky merino by 1,4 %. There was no diff erence between the breeds by the ratio of secondary follicles/primary follicles.