PECULIARITIES OF THE SKIN HISTOSTRUCTURE OF THE NEW SEMI-COARSE-WOOLED TYPE OF THE ANDEAN SHEEP BREED

Abstract

In order to improve and preserve coarse-wooled sheep, gene pool farms for each breed were created in the Dagestan. The research established that there were two basic types in the herds of the Andean breed of the white population: coarse-wooled and semi-coarse-wooled. At the same time, sheep of the semi-coarse-wooled type exceeded the coarse-wooled ones in live weight, wool yield and its quality parameters, which indicated the expediency of creating a semi-coarse-wooled type in the coarse-wooled Andean breed. A part of the problem of understanding the patterns of individual development of animals is the study of the formation of the skin structure and wool quality, which has not only general biological but also great practical significance, especially in sheep, since fleece is their main product. In this regard, the conducted studies allowed us to provide a scientific basis for the correct development of measures, which were aimed at increasing wool production, the quantity and quality of which largely depended on the skin structure.

The obtained research results indicated that based on the previous and latest studies on comparison of the coarse-wooled Andean breed and the populations of the semi-coarse-wooled type, which were selected from this breed, the results with higher meat and wool productivity were obtained. This was confirmed by the stage of the study of sheepskin products, histological examination of skin samples, where the advantage of the new semi-coarse-wooled type of young animals was in terms of skin thickness and skin layers – the papillary dermis by 6,3%, the reticular layer by 5,0% and the total skin thickness by 5,8%, and by the total density of hair follicles – by 4,2%, by the ratio of HF/PF – by 22,2%, which showed a slightly larger meat (slaughter weight by 7,4%) and wool productivity (wool yield in clean fiber by 8,2%).