Romanovych L. Biochemical mechanisms of the effect of vitamin E and C supplements on the immune potential and antioxidant protection of broiler chickens.

The purpose of the scientific work was to determine the effect of separate and complex introduction to the diet of broiler chickens of vitamins E and C on the indicators of protein and lipid metabolism, hematological profile, activity of immune and antioxidant protection, their growth and viability. Studies have shown that additional introduction of vitamins E and C to the diet of broiler chickens during the period of their breeding caused a decrease in the content of lipid hydroperoxides (LHPO) and tiobarbituric acid reactive substances (TBARS) in blood plasma (P<0.05-0.001) and aldehyde and ketone derivatives in serum, which indicates the inhibitory effect of the studied vitamin supplements on the intensity of the of lipid peroxidation (LPO) and oxidative modification of proteins (OMP) in the blood. The use of dietary supplements of vitamins E and C in chickens caused an increase in the content of reduced glutathione, glutathione peroxidase and superoxide dismutase activity (P<0.05). These changes were more pronounced in chickens of the experimental groups at 34th and 41st days of age, and especially with the combined use of vitamins E and C. The higher content of total lipids in the liver and skeletal muscles of chickens of all experimental groups at 27 days of age than in the control (P<0.05-0.01) was found. The content of phospholipids and diacylglycerols in the skeletal muscles of chickens fed vitamin E supplementation was 1.5 (P<0.05) and 1.4 times (P<0.01) higher, respectively, and the content of free cholesterol and triacylglycerols in 1.7 (P<0.01) and 1.2 (P<0.05) times less than in chickens of the control group. Under the conditions of separate application of supplements of vitamins E and C to compound feed, a probable decrease in the relative content of linoleic acid in the total lipids of liver tissues of broiler chickens of 27- and 41-day-old age was recorded. The decrease in the content of linoleic acid in the liver of chickens of the first and second experimental groups in this period of the study was accompanied by a simultaneous increase in the relative proportion of arachidonic acid. The influence of the studied vitamin supplements on the content of oleic, stearic and palmitic fatty acids is characterized by a similar diversity. When analyzing the data on the fatty acid composition of total lipids of the thigh muscles of broiler chickens, the relatively high content of linoleic and oleic fatty acids, which is 30.4-38.3 and 25.5-28.3 of the total fatty acids, attracts attention. Feeding tocopherol acetate and ascorbic acid supplements resulted in a significant increase in the relative linoleic acid content of chicken thigh muscle lipids. These changes were expressed to a greater extent by the action of vitamin E, as well as the combined use of vitamins C and E – by about 8%. At the same time, under the influence of supplements of vitamins E and C to the diet of chickens, a decrease in the relative content of another unsaturated fatty acid – oleic, in particular, by 2-3 %.