Nano selenium and plant extracts supplementation enhanced reproductive performance of parity-2 sows

To investigate the effects of nano selenium (nano-Se), curcumin (CUR), and glycyrrhiza extracts (GE) on reproductive performance, antioxidant and immune functions of primiparous sows and parity-2 sows, 54 primiparous sows (Landrace × Yorkshire) were randomly divided into three groups (18 sows per group): (1) CON group, basal diet (0.30 mg·kg^-1 Se, sodium selenite); (2) CUR group, basal diet + 0.20 mg·kg^-1 Se (nano-Se) + 300 mg·kg^-1 CUR; (3) GE group, basal diet + 0.20 mg·kg^-1 Se (nano-Se) + 500 mg·kg^-1 GE. The trial lasted for approximately 180 days from day 90 of gestation of primiparous sows to parity-2 sows. There were no significant differences in reproductive performance among three groups (p > 0.05), but the litter weight gain of piglets from primiparous sows in the GE group was 16.49% higher than that in the CON group (p < 0.05). Compared with the CON group, the serum SOD and GSH-Px levels of primiparous sows in the GE group were significantly increased, and the MDA content was extremely decreased. The concentrations of serum IL-6 and IL-1β (p < 0.05) of primiparous sows in the GE group were significantly lower than those in the CON group, and the serum IL-10 and TNF-α concentrations (p < 0.05) was significantly higher. The combination of nano-Se and CUR decreased the serum IL-1β level and increased the TNF-α concentration (p < 0.05). In conclusion, the addition of nano-Se along with CUR or GE in the diet of primiparous sows significantly increased the antioxidant and immune levels in the serum of primiparous sows at parturition, enhanced their stress resistance, and thus improved growth performance of offspring piglets and reproductive performance of parity-2 sows.