The success of artificial insemination (AI) in the swine industry relies on conserving the quality of boar sperm during liquid storage, as boar spermatozoa are prone to oxidative stress due to the high polyunsaturated fatty acid content and lack of antioxidant defenses. Sperm motility, viability, acrosome integrity, and DNA stability are all affected by the increases in reactive oxygen species (ROS) during storage, which lowers fertility. Ethyl pyruvate (EP), a stable derivative of pyruvate, has good antioxidant properties and has been shown to protect sperm quality in vivo. Its effects on boar sperm during in vitro preservation have not yet been investigated. This study investigated the effect of different concentrations of EP (0.1–1 mM) in Beltsville thawing solution at 17°C on the sperm quality parameters of boar spermatozoa over five days. Changes in sperm motility, viability, acrosome integrity, chromatin stability, and ROS were observed. The results showed that boar spermatozoa stored with 0.25–0.75 mM EP showed a significant increase in sperm motility, viability, acrosome integrity, and chromatin stability compared with the control (without EP) and 1 mM EP for 5 days. Compared to the control and 1 mM EP, ROS levels statistically decreased in sperm stored in 0.25–0.75 mM EP on both storage days 3 and 5. Our findings demonstrated that 0.25–0.75 mM of EP could enhance the boar sperm quality and mitigate the oxidative stress during liquid storage, thus revealing a strategy to improve fertility rates during AI in pig production.

We have studied the technology to extend the storage period of ‘Seolhyang’ strawberries using modified atmosphere package (MAP) and ethyl pyruvate (EP) treatment for domestic distribution and export. The selected ripe strawberries harvested on December 28, 2016 at the Sancheong farmhouse were transported to the laboratory for 2 h and tested. After a day’s precooling at 4℃, the strawberries were divided into seven experimental groups. These groups were control, active MAP using low density polyethylene (LDPE), active MAP using polyamide (PA), active MAP using PA with EP treatment, passive MAP using LDPE, passive MAP using PA and passive MAP using PA with EP treatment. Quality analysis was carried out every 4 days during the storage period of 16 days. During the storage period of 16 days, MAP decreased from 3.5% to less than 1.1% in weight loss ratio compared with control, and decreased from 36% to less than 7% in fungal incidence. In the case of fungi in the EP treatment group, hyphae did not grow on the outside of the strawberry but grew to the inside. This tendency was similar to that in the low oxygen and high carbon dioxide environment of the MAP, the mycelium of the fungus did not grow outside of the strawberry. Fungi are the biggest problem in the distribution and export of strawberries, and these results suggest that MAP alone could inhibit mold and increase shelf life.