Effect of Illicium verum or Eucommia ulmoides leaf extracts on the anti‐stress ability, and mRNA and protein expression of Nrf2 and TNF‐α in Duroc × Landrace × Yorkshire and Chinese native Licha‐black nursery piglets

Plant extracts are considered to be an effective alternative to antibiotics in response to weaning stress in piglets. This study evaluated the effect of Illicium verum extracts (IVE) or Eucommia ulmoides leaf extracts (ELE) on growth performance, serum and liver antioxidant ability of nursery piglets, as well as the difference of IVE and ELE on Duroc × Landrace × Yorkshire (DLY) and Chinese native Licha‐black (LCB) piglets. A total of 96 nursery piglets (48 DLY and 48 LCB piglets) with an average body weight of 11.22 ± 0.32 kg were randomly divided into four treatments in a 2 × 4 factorial design. Each treatment had four replicates with 3 DLY and 3 LCB piglets per replicate respectively. Treatments included: basal diet, basal diet + 500 mg/kg IVE, basal diet + 250 mg/kg ELE and basal diet + 50 mg/kg chlortetracycline (CHL). All piglets were housed individually for the 42 days trial period after 7 days adaptation. Results showed that there were significant interactions (p