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