Influence of vitamins on the prooxidant-antioxidant homeostasis in boars under the conditions of heat stress

The intensity of reproduction of the live-stock of pigs largely depends on environmental factors, in particular fluctuations in indoor temperature, which is often seasonal. It was found out the fact that in the summer with a long rise in temperature it is worsened the quality of sperm in boars, which is accompanied by a decrease in the fertility of sperm, and in multiplicity and large foetus fertility of sows. The aim of the study was to determine the influence of antioxidant vitamins on the prooxidant-antioxidant homeostasis in  blood of boars under the conditions of heat stress. In the study it was used the adult boars of the Large White breed. The duration of the experiment was 120 days, including: preparatory one is 30 days, basic one is 60 days (feeding vitamin A, vitamin E, ascorbic acid) and final one is 30 days. In the main period of the experiment, the diet of animals in the control group remained unchanged, and it was for  two experimental ones with the addition of vitamin A, vitamin E and ascorbic acid. The level of biologically active components in the diet of the experimental groups was higher by 10 % and 20 % compared with the control group. In the received blood samples it has been  determined  the state of prooxidant-antioxidant state. It has been determined that housing boars in conditions of increased temperature is accompanied by the acceleration of peroxidation processes and the depletion of the antioxidant defense system in  blood. The introduction of a vitamin supplement in the feed mixture to boars significantly changes the state of prooxidant-antioxidant homeostasis in this tissue depending on the amount of additionally fed vitamins with antioxidant action. The addition of these biologically active substances by 10 % above the norm after 60 days of feeding increases the content of vitamin A (P < 0.05), vitamin E (P < 0.05), reduced glutathione and slows down the processes of peroxidation – reducing the concentration of diene conjugates (P < 0.01) and TBA-active complexes. Feeding vitamins with antioxidant action in the feed mixture is 20 % more than the norm for boars, compared with the control group, after a month of the use, inhibits peroxidation processes. Two months of using  these compounds probably reduced the number of diene conjugates (P < 0.01) and TBA-active complexes. It is accompanied by an increase in the content of low molecular weight antioxidants – vitamin A (P < 0.01), vitamin E (P < 0.05) and ascorbic acid, the level of which is maintained for at least a month after their use.