Strohush N. Characteristics of skin and wool lipid composition of different sheep breeds and their correlation with wool growth, physical and chemical parameters of wool.

The object–the age, season and breed features of the skin lipids, skin histostructure, physical and chemical characteristics of wool of fine-fleece sheep (Precos breed) and semicoarse-fleece sheep (Ukrainian Carpathian breed). The aim–to find out the age and species characteristics of skin and wool lipid composition, their correlation with physical and chemical parameters of wool, the impact of season, physiological status of the organism, feeding and maintaining of animals. Methods: biochemical (the thin-layer chromatography, the chemical composition of wool), physical (the strength and thickness of wool), histological (the mitotic activity of hair follicles, thickness of skin and its layers), zootechnical (the wool growth), statistics. Novelty: for the first time, the season, breed and the age features of the lipid composition of the sheep's skin and the interrelation between chemical and physical indexes during annual wool growth, breed and season characteristics of the skin histostructure were investigated. There are also firstly investigated the age and breed features of the content and composition of the internal wool lipids of the Precos sheep and the Ukrainian Carpathain sheep and their correlation with chemical and physical properties of wool. Results:it has been shown wool growth during different season periods accompanied by changes of skin lipid indexes, histological characteristics of skin, physical and chemical parameters of wool. The skin of semicoarse-fleece sheep characterized by lower lipid metabolism compared to fine-fleece ewes. The most part of internal wool lipids both sheep breed takes place the covalently bound fraction (1,15 - 2,18 %). The neutral lipids are predominant among internal lipids. Cholesterol is dominant fraction of neutral lipids, and ceramides are dominant part of polar lipids. The cholesterol sulfate content in the free internal lipids of wool can be used as the marker for evaluation of fibers quality. It has been proposed the method of prevention wool growth inhibition in ewes in winter-stall period by addition the biological active food additive to their diet. Area of use - biochemistry, sheep-breeding.