Assessment of the relationship between the level of somatotropin in hair and meat qualities of Hereford bulls

Background.The issue of using hair as an indicator of long-term changes in somatotropin metabolism in the body of young bulls has not been sufficiently addressed. Moreover, there is almost no information on the relationship between the somatotropin level in hair and the meat qualities of young bulls, which determined the relevance of this study. Objectiveis to study the effect of the somatotropin exchange pool, estimated by its concentration in hair on the meat qualities of the Hereford bulls. Materials and methods.The studies were performed on the Hereford bulls. Animals were divided into three groups depending on the somatotropin level in hair: I - (53.4-57.1 pg / mg); II - (57.3 to 61.8 pg / mg); III - (62.1 to 67.1 pg / mg). Results. Bulls with the maximum somatotropin level had the highest rates of weight gain. Animals of this group had higher slaughter weight and meat protein content, with a lower fat content. An increase in the somatotropin concentration in hair was accompanied by an increase in the concentrations of leucine + isoleucine, tryptophan, histidine, methionine, a decrease in phenylalanine and serine, as well as an increase in the concentrations of polyunsaturated fatty acids in the longissimus dorsi muscle. The longissimus muscle of bulls with the maximum somatotropin level in hair contained more calcium, copper, zinc and iodine, with relatively low lead concentrations. Conclusion.The level of somatotropin concentration in hair from the withers is closely related to the intensity of weight growth, meat productivity and meat quality of Hereford bulls, which allows us to consider hair as a biosubstrate for assessing long-term changes in the level of somatotropin in the body, when developing measures aimed at increasing the meat productivity of bulls.