Oxidative stress status and reproductive performance of sows during gestation and lactation under different thermal environments.

Objective: Two experiments were conducted using 28 healthy multiparous sows to evaluate the oxidative stress status and reproductive performance of sows during gestation and lactation under different thermal environments.
Methods: Fourteen multiparous sows were used in Exp. 1 under a high thermal environment, and the other 14 multiparous sows were used in Exp. 2 under a moderate thermal environment. In both experiments, reproductive performances of sows were recorded. Plasma samples were collect on d 35, 60, 90, and 109 of gestation, and d 1 and 18 of lactation for malondialdehyde, protein carbonyls, 8-hydroxy-deoxyguanosine, IgG, and IgM analysis.
Results: For sows in Exp. 1, plasma malondialdehyde concentration on d 109 of gestation tended to be greater (p < 0.05) than it on d 18 of lactation. Plasma concentration of protein carbonyl on d 109 of gestation was the greatest (p < 0.05) compared with all the other days. Plasma concentrations of 8-hydroxy-deoxyguanosine on d 109 of gestation was greater (p < 0.05) than d 18 of lactation in Exp. 1. For sows in Exp. 2, there was no difference of malondialdehyde and protein carbonyl concentration during gestation and lactation. In both Exp. 1 and 2, litter size and litter weight were found to be negatively correlated with oxidative stress indicators.
Conclusion: Sows under a high thermal environment had increased oxidative stress during late gestation indicating that increased oxidative damage to lipid, protein, and DNA could be one of the contributing factors for reduced reproductive performance of sows under the high thermal environment. This study indicates the importance of providing a moderate thermal environment to gestating and lactating sows to minimize the increase of oxidative stress during late gestation which can impair reproductive outcomes.