THE EFFECTIVENESS OF GROWING RAINBOW TROUT AT DIFFERENT LEVELS AND RATIOS OF LYSINE AND ARGININE IN GROWER COMPOUND FEED

Abstract

The article highlights the results of the study of the influence of different levels and ratios of amino acids lysine and arginine in compound feed for commercial rainbow trout. The experiment was conducted on 6 groups of grower rainbow trout, 100 specimens in each. The fish were injected with 2.0 to 3.2% arginine against the background of lysine content in the first three groups – 2.8%, and 4–6 groups – 3.0%. The level of the studied factors was regulated by the introduction of synthetic preparations of amino acids. The ratio between arginine and lysine ranged from 0.71 to 1.14. Combined feed was distributed 2 times a day at the rate of 2% of the weight of the fish. Effective levels of lysine and arginine in compound feed for commercial trout have been experimentally established. The highest body weight and gains, the lowest feed ratio were observed when the compound feed contained 3.0% lysine and 3.2% arginine, with an arginine-lysine ratio of 1.07 : 1. For increasing the level of arginine in commercial rainbow trout compound feed from 2.0 up to 3.2% against the background of lysine content of 2.8%, an increase in body weight by 0.48 - 2.01% was noted; absolute, average daily and relative growth, respectively by 1.32 - 2.06%, 0.80 - 1.60% and 6.33 - 7.93%; feed costs decreased by 0.56 - 0.69%. An increase in the level of arginine in compound feed to 3.2% against a background of 3.0% lysine led to an increase in the body weight of trout by 1.05-2.64% (р˂0.01), absolute growth - by 1.52-3.65 % (р˂0.01), average daily increase - by 0.79 - 3.17% (р˂0.01), relative increase - by 9.77 - 21.84% (р˂0.01). Feed consumption per 1 kg of gain decreased by 0.87% at the arginine level of 3.2% and remained practically unchanged at the arginine level of 3.0%. An increase in the content of lysine in trout feed to 3.0% against the background of the basic level of arginine - 2.8% caused a slight increase in the body weight of fish - by 0.30 - 0.60%; of absolute, average daily and relative growth, respectively by 0.65; 0.80 and 1.28%. Feed costs decreased by 0.62%. No relationship was noted between the arginine-lysine ratio in compound feed and the growth indicators of rainbow trout, nor were there any antagonism phenomena between the studied amino acids.