Hematological and biochemical indicators of rainbown trout blood depending on lysin and methionine levels in feed

The effect of use of complete feed with different lysine and methionine levels on the hematological and biochemical indicators of rainbow trout blood is studied in the article. The aim of the experiment was to establish the effect of different levels of amino acid nutrition of commercial rainbow trout on hematological and biochemical indicators of its blood. For this purpose, five experimental groups were formed by the analog method. The study lasted 210 days and was divided into two periods: equalizing (10 days) and basic (200 days). In the equalizing period, the trial fish consumed feed of the control group. In the basic period of the experiment, the level of lysine and methionine in the production feed ranged from 2.5 to 2.9% and from 0.8 to 1.0%, respectively. It was found that the different content of lysine and methionine in the diets of two-year-old rainbow trout did not cause significant changes in biochemical indicators of blood. The increase in the content of limiting amino acids in the combined feed of young rainbow trout caused slight deviations in hemoglobin content compared to control. The analysis of the obtained results revealed the highest content of erythrocytes (1.28 T/l) in the blood of specimen of experimental group 5, the level of amino acids in combined feeds was the lowest. Its highest content was found in the blood plasma of trout of experimental group 4, which received combined feed with a content of 2.8 % lysine and 0.95 % methionine. The concentration of total protein in the blood serum was almost the same in all experimental groups of commercial rainbow trout. It was found that different levels of amino acid nutrition of rainbow trout did not affect the dynamics of changes in the blood cell morphology differentials.