Effect of the Addition of α-Tocopherol and Quercetin as Antioxidants to the Diluent, in the Freezing of Boar Semen on Sperm Quality

During seminal freezing, sperm undergo oxidative stress, reducing their motility, viability, and acrosomal integrity. To prevent these damages, antioxidants have been added at the time of seminal freezing. The objective was to assess the antioxidant effect of the combination of α-tocopherol with quercetin, added to the diluent for the freezing of boar semen. The semen of boars of the Pietrain and York/Pietrain breeds was frozen in 0.5 ml straws, before freezing α-tocopherol in a concentration of 4 mg/ml (T1), quercetin in concentrations of 25, 50 and 100 µM (T2, T3 and T4), α-tocopherol + Quercetin in concentrations of 4 mg/ml + 25 µM, 4 mg/ml+50 µM and 4 mg/ml + 100 µM (T5, T6 and T7) and the control group (T8) without antioxidant. The straws were frozen in liquid nitrogen for 7 days and thawed at 42 °C for 12 seconds. 5 repetitions were performed analyzing motility, viability, and NAR. the results were analyzed using a completely randomized design in factorial arrangement comparing the means with a Tukey test. The best percentage of motility was for T5, T4 and T1 with 39.44, 38.06 and 37.33%, respectively, there was a significant difference with T8; the best percentage of viability were T5 with 51.41%, there was a significant difference with T3 and T8; and the best NAR percentages were for T8 with 94.90%, with a significant difference for T1. In conclusion, the addition of α-tocopherol and quercetin separately or in combination protects the motility, viability, and NAR of spermatozoa from frozen-thawed boar semen.