Protein nutrition of poultry can be regulated at the level of individual amino acids with the help of feed additives improving the amino acid profile of compound feed. The purpose of the research is to evaluate the effect of the feed additive synthetic L-valine, the fourth limiting amino acid for broilers, to the basic compound feed with a reduced protein content on the nutrient digestibility, amino acid composition of muscles and zootechnical indicators of broiler chickens. The study was conducted at OOO “Timashevskaya Poultry Farm”. We have formed 4 groups of chickens 500 head each. Chickens from the experimental groups received an additive of synthetic L-valine in compound feed in the amount of 0.04–0.150%; chickens of the control group received a basic diet without valine additives. Together with the additives of the limiting amino acids lysine, methionine and threonine, the addition of crystalline L-valine improved the amino acid profile of the compound feed. Nutrient digestibility was higher in the experimental groups than in the control group. The highest rates were recorded in the group Experiment 2: dry matter was 78.31%, crude protein – 88.85%, crude fiber – 22.42%, and crude fat – 82.77%. The valine content in the muscles of the breast and thigh turned out to be higher in the experimental groups receiving compound feed with the inclusion of valine additives than in the control groups. Its content in the breast muscle is greater, compared to the thigh muscle. The largest amount of valine was in the group Experience 3: 4.838% was in the breast muscle and 4.298% was in the thigh muscle. Broiler chickens from the experimental groups, receiving compound feed with additional valine, had the highest average daily weight gain of 59.5 g, the average live weight of a chicken was 2.31 kg, feed conversion was 1.70, gross meat yield was 1098 kg. These indicators are better than in the control group. The highest productivity index among the experimental groups was 350.6 which is also higher than in the control group
Keywords
protein, Broiler chickens, Protein, limiting amino acids, valine, broiler chickens, productivity index