Influence of feed additive with low degree of protein degradability on indicators of nitrogen metabolism in steers body during fattening

Abstract

The development of beef cattle breeding and obtaining high-quality beef in Russia is currently one of the important tasks. The results of investigations on the influence of a feed additive with a low degree of protein breakdown on the efficiency of nitrogen use in the body of fattening steers and their productivity traits have been presented in the paper. The ration of steers included the feed additive as the source of hard-to-break down protein, which includes components of animal origin (feather fl our, fi sh meal, poultry waste), which have the high biological value of protein and its low degradation in the rumen. The feed additive was introduced into the daily ration at a dose of 1,5 g/kg of live weight. The accounting period of the experiment was 92 days. The degree of protein breakdown in the feed additive was determined on fistula animals in sacco, which was 55,2 %. The feed additive contains (%): 40–43 crude protein, 20–25 crude fat, 2,2 lysine, 1,9 methionine, 2,6 tryptophan, 1,5 calcium, 6,5 phosphorus. It has been found that the introduction of the protein additive with the low protein breakdown in the dose of 1,5 g/kg of live weight into the ration of steers had the positive influence on the indicators of the biochemical composition of blood, digestion in rumen, promoted better use of feed nitrogen and increased the productivity of fattening steers. There were significant differences in the increase in nitrogen deposition in the body of the experimental group of steerls by 29,5 %; the coefficients of nitrogen use from the feed consumed and from the digested increased by 5,57 and 7,71 abs.%, respectively. The average daily weight gain of the steers in the experimental group was 1102,17 g, which was 11,79 % higher compared to the animals of the control group that did not receive the protein additive. The research results indicate the effectiveness of the use of protein feed additive in the ration of young cattle during fattening.