Changes of the skin and wool coat of sheep of fi ne-wool breeds related with age

Abstract

Sheep breeding is a unique branch of animal husbandry, characterized by a variety of products: wool, meat, milk, sheep pelts. The successful development of the industry is largely determined by the development of modern technologies, the creation of new genotypes that make it possible to produce competitive, high-quality products that meet market demands as much as possible at the lowest cost. In sheep breeding in the North Caucasus and Southern Federal Districts for many decades and up to the present, the fine-wool direction has a signifi cant share. The purpose of the research was to identify the effectiveness of the use of objective indicators of the basic properties of the skin and wool coat of sheep in the breeding process. In a comparative aspect, the indicators of wool productivity and histostructure of the skin of sheep of fi ne-wooled breeds such as Stavropol, Manych merino and Dzhalginsky merino at the age of 4,5 months (when weaning) and 1,5 years. The results of studies of the skin and hair coat, which revealed that in the period from 4,5 months to 1,5 years, the total thickness of the skin of experimental animals increased in the breeds Stavropol, Manych merino and Dzhalginsky merino by 14,2; 13,0; 12,2 %, respectively. The increase in the depth of both primordial and secondary follicles occurred by 12,3, 13,4 and 12,9 %, respectively, in the breeds Stavropol, Manych merino and Dzhalginsky merino. In the studied breeds, the density of hair follicles per mm2 decreased by 17,3 %, 9,4 and 8,2 %, respectively, but the ratio of secondary follicle/primordial follicle remained unchanged. The results of a comprehensive assessment of the fl eece revealed that both quantitative and qualitative indicators on the score scale had an excellent rating. The use of rams with established characteristics in the breeding campaign on the ewes of the breeding core will contribute to the production of young animals with the specified most productive indicators.