The effect of zinc chelate and antioxidant vitamins on the quality of sperm production and the state of pro-oxidant-antioxidant homeostasis in breeding boars

The increase in temperature in pig housing during the summer negatively affects their reproductive capacity, causing heat stress. This leads to a decrease in boar sexual activity, a reduction in sperm concentration in the ejaculate, and a decline in their biological integrity. The primary causes of these changes include the oxidation of unsaturated fatty acids in sperm membranes and an imbalance in the prooxidant-antioxidant system. A study on the effect of a complex vitamin-mineral feed supplement on sperm quality was conducted on Large White breeding boars, selected as age, body weight, and sperm quality analogs. They were divided into three groups of three individuals each: a control group and two experimental groups. The experiment lasted 120 days, including a 30-day preparatory period, a 60-day main period (supplementation with vitamins A, E, C, and chelated zinc), and a 30-day final period. The diet of the control group remained unchanged, while the first experimental group received a 5 % increase in components, and the second received a 10% increase. The experiment showed that under heat stress, the ejaculate volume in the first and second experimental groups was 21.1 % (P < 0.05) and 22.4 % (P < 0.01) higher, respectively, compared to the control group. Sperm concentration exceeded control values by 17.2 % on day 60 and by 10.9 % in the final period, while sperm motility increased by 21.5 % (P < 0.001) and 13.1% (P < 0.05), respectively. An analysis of lipid peroxidation indicators revealed that the level of diene conjugates in the sperm of the control group increased by 73.5 % (P < 0.001) by day 60. Meanwhile, in the experimental groups, their level was 40.05 % (P < 0.01) and 24.0% (P < 0.05) lower compared to the control group, indicating the antioxidant effect of the vitamin supplement and chelated zinc. In the control group, the levels of superoxide dismutase and catalase increased by 36.4 % (P < 0.05) and 44.6 % (P < 0.01), respectively, which is a sign of oxidative stress. At the same time, in the experimental groups, catalase activity and the level of reduced glutathione remained more stable, demonstrating the protective effect of the feed supplement. The increase in temperature during the summer negatively affects boar sperm production, causing heat stress, which reduces sperm concentration and motility. The addition of antioxidant vitamins (A, E, C) and chelated zinc to the diet helps maintain sperm quality and quantity, reduces oxidative stress levels, and stabilizes the body's antioxidant status. Using such a feed supplement supports high reproductive capacity in boars and mitigates the negative effects of elevated temperatures.