Protective properties of the fleece of Taurian ewesof the Askanian fine fleece breed depending on the breeding differentiation rank

Abstract

The study of factors affecting the humidity and contamination of the outer and inner zones of the staple, which further affects the yield of pure wool and its technological properties, is one of the current problems of fine-fleeced sheep breeding. Purpose of the study – evaluate the protective properties of wool fleece depending on the rank of breeding differentiation of sheep. The determination of ranks is based on the regularities of the normal distribution of animals in the population and herd reproduction indicators. 10 ranks were used. The paper presents the results of a laboratory study of the content of mineral impurities and the degree of contamination of the staple. Sheep were divided into 10 ranks of breeding differentiation. The regularities of the normal distribution of animals in the population are considered. The obtained data indicate that the variety of sheep in terms of the content of mineral impurities in wool is very large. The coefficient of variation is 35% with a variation in the ranks of breeding differentiation from 13.7 to 38.4%. With an increase in the group of the total value of sheep for breeding purposes, the value of the coefficient of variation decreases (rs=-0.871±0.245). With an increase in the ranks of breeding differentiation, the average absolute indicators of contamination of the outer zone of the staple tend to increase (rs = +0.257 ± 0.483), and the relative values decrease (rs =-0.600 ± 0.400). The average absolute contamination rate of the inner zone of the staple is 3.02 cm with a range of ranks from 2.83 to 3.29 cm. According to the relative degree of contamination, these indicators are 32.5% and from 31.0 to 35.2%, respectively. With an increase in the breeding differentiation rank of sheep, the absolute indicators of contamination of the length of the inner zone of the staple increase (rs = +0.600 ± 0.400), and relative values tend to decrease (rs =-0.486 ± 0.437). The individual variety of ewes in terms of the degree of contamination of the inner zone of the staple is quite high. The coefficients of variation for absolute and relative indicators of this feature are 28.5 and 30.4%, respectively. The value of the coefficients of variation decreases slightly with an increase in the ranks of breeding purposes of animals. The rank correlation is -0.371 ± 0.464 in absolute terms and -0.543 ± 0.420 in relative terms. Breeding differentials of the leading groups of ewes are low. Using this rank technique allows controlling the system of sheep valuation, supplementing it with the value of breeding differentials at the final stages of analysis and selection; in production conditions allows forming technological groups of sheep to produce outstanding ram breeders