Rationing of non-degradable protein in diets for breeding steers

Abstract

Abstract The paper provides the results of research on development of standards for non- degradable protein in diets for replacement steers of black-and-white breed. Studies were conducted in 3 groups of repair steers aged 12- 18 months, with an average initial body weight of 363-367 kg. Differences in feeding consisted in the fact that the amount of non-degradable protein in diet for steers in the control group was 10% lower than the accepted standard, in II group – corresponded to the accepted standard, in III group – 10% higher than standard. It has been determined that animals of II and III experimental groups, consuming diets with increased level of non-degradable protein, better digested dry and organic matter, and protein by 6.4 and 6.9; 6.4 and 7.1; 5.6 and 5.5 p.p. However, there was an increase of total protein by 4%, total and protein nitrogen – by 4-5% in blood of steers of the II experimental group, while in young animals of III experimental group these indicators increased respectively by 6.5 and 7%. The average daily weight gain of steers of the experimental groups increased by 3 and 5%, ejaculate volume – by 11-14%, sperm cells count – by 9-12%, amount of energy deposited in weight gain – by 4.1-9.0%, diet energy consumption per 1 MJ deposited in weight gain decreased by 4-5 %.