Elimination the impact of heat stress by supplementation of antioxidants into diet of duroc boars

Abstract

The aim of this experiment was to find out, if is it possible to eliminate the impact of heat stress on quality of Duroc boar ejaculate by the addition of complex of antioxidants (Selenium, Zinc, Vit. C and Vit. E) into the basic diet. The experiment was carried out at the station of insemination in Velke Mezirici (Czech Republic) from May to September. For the study were chosen 12 Duroc boars, of approximately the same age and weight, and were divided into two groups. The control group (n = 6) was fed only by basic diet, the experimental group (n = 6) was fed by basic diet with the supplementation of antioxidants in amount: 0.5 mg selenium (seleno-methionine), 70 mg zinc (zinc-methionine), 70 mg vit. E (alpha-tocopherol) and 350 mg vit. C (L-ascorbic acid) per kilogram of basic diet. Monitored parameters of ejaculate was volume of ejaculate (ml), concentration of sperm (106/ml), total rate of sperm (109), motility of sperm (%) and amount of morphologically abnormal sperm (%). The control group reported slight increase in volume of ejaculate (of 19 %), which is common in summer months. At the same time was the concentration of sperm unstable, during August there was an increase of 15 %, but during September concentration decreased below the initial amount. Motility was around 69 % during whole experiment. There was an increase (of 15 %) in amount of morphologically abnormal sperm, but the result was insignificant. The experimental group had a higher volume of ejaculate, but the diagram of volume of ejaculate was almost the same with the control group. Concentration of sperm increased after the supplementation of antioxidants (of 23 %) and during the experiment decreased only slightly. Motility was about average amount 70 % and was not various during the experiment. In amount of morphologically abnormal sperm there was an increase about 12 %. According to the results, the supplementation of antioxidants had no significant effect on improving of semen quality. But the addition could have a positive effect to stable the parameters of ejaculate.