Oxidative Status of Boar Semen during Storage

The intensification of the use of artificial insemination in the swine industry has increased the interest to develop proper conditions to store semen better for longer periods of time without affecting its fertility. Trolox is a vitamin E analog with antioxidant property to prevent oxidative stress. Therefore, the objective of this study was to evaluate the Trolox antioxidant capacity on boar semen during storage period (86 h) at 15°C. For that, semen samples from 5 different boars were collected and diluted with a Long-Term (LT) extender with and without the addition of Trolox in a concentration of 50 µM. The sperm motility, oxidative stress and antioxidant protection were measured in those samples during an 84 h storage time. Our results indicated that Trolox was able to minimize the loss of sperm motility after 24 h of storage. The storage time was positively correlated with TBARS production. However in the presence of Trolox, after 12 h, TBARS content were significantly lower than those of sperm cells stored with LT diluent only. The concentrations of Non-Protein SH groups (NPSH), after 36 h of storage, were lower in sperm cells stored only with LT diluent when compared to the group supplemented with Trolox. Catalase and Superoxide Dismutase activities were decreased after 48 h storage at 15°C in both groups (with or without Trolox). Spontaneous spermatozoa ROS formation was high in viable swine sperm during the LT storage period in samples without Trolox. In conclusion, LT diluent with the addition of antioxidant as Trolox can reduce the oxidative stress in sperm cells, which could be used to protect spermatozoa against oxidative damage, preventing motility losses in swine semen.