Effect of the level of somatotropin hormone in blood serum on the meat productivity of Aberdeen angus bulls

¹ Federal Scientific Center for Biological Systems and Agrotechnologies of the Russian Academy of Sciences, Orenburg, Russia
² Russian State Agrarian University – Moscow Agricultural Academy named after K. A. Timiryazev, Moscow, Russia

^* Corresponding author: Oleg-zavyalov83@mail.ru

Abstract

The studies were performed on Aberdeen Angus bulls at the age of 18 months. Animals, depending on the level of somatotropin in blood serum, were divided into three groups by the percentile method: group I – up to the 25th percentile; group II – within the limits of 25-75 percentiles; group III – above the 75th percentile. The somatotropin content was determined in blood serum by enzyme-linked immunoassay using an automatic microplate analyzer Infinite F200 PRO. To study the meat qualities of steers, a control slaughter was carried out at the age of 18 months. It was found that animals with the maximum level of somatotropin in the blood serum had a higher pre-slaughter mass, hot carcass weight, chilled carcass, pulp mass and bone mass, with a minimum content of internal fat in the carcasses. The chemical composition of the average sample of meat and the longest back muscle in these animals was characterized by an increased protein content and a minimum fat concentration. The protein-qualitative indicator estimated by the ratio of tryptophan to oxyproline in the longest back muscle increased with an increase in serum somatotropin.