Abstract: This study was conducted to determine the effect of compound Chinese herb ultrafine powder on the antioxidant ability of laying hens during late laying period. A total of 216 Xinyang black-feather laying hens at 307-day-old were selected and randomly divided into three groups, with eight replicates per group and nine hens per replicate. The birds in control group was fed a basal diet, and the experimental groups were supplemented with 0.5% Salvia miltiorrhiza (SM) + 0.25% Ligustrum lucidum (LL) + 0.25% Dandelion (Compound 1) and 0.3% Motherwort + 0.2% SM + 0.25% LL + 0.25% Dandelion (Compound 2) ultrafine powder, respectively. Samples of plasma and liver tissue were collected on days 60 and 120 of the trial to measure oxidation-antioxidant indexes and related gene expression. The results showed that, compared with the control group, on day 60 of the trial, the plasma and liver MDA content were decreased and the mRNA expression levels of liver NQO1 and GST were upregulated in compound 1 group (P<0.05), the mRNA expression levels of liver GSH-Px2, GSH-Px3, GSH-Px4, SOD2, SOD3, TXNRD1, TXNRD3, NQO1 and HO-1 were up-regulated (P<0.05) in compound 2 group, while the liver activities of GSH-Px, SOD, CAT and T-AOC were increased (P<0.05) in both compound 1 and 2 groups; On day 120 of the trial, the liver MDA content was decreased (P<0.05) in compound group 1, the plasma CAT activity was increased (P<0.05) in compound 2 group, the mRNA expression levels of liver Nrf2 and GSH-Px2 were increased (P<0.05) in compound 2 group, and the liver GSH-Px, SOD and CAT activities were increased (P<0.05) in compound 1 and 2 groups. Compared with the compound 1 group, on day 60 of the trial, the mRNA expressions of liver CAT and GST were decreased (P<0.05) in compound 2 group, and the liver mRNA expression levels of GSH-Px2, GSH-Px3, GSH-Px4, SOD2, SOD3, TXNRD1, TXNRD3, NQO1 and HO-1 were increased (P<0.05) in compound 2 group; On day 120 of the trial, plasma MDA content and mRNA expressions of liver Nrf2, GSH-Px2, TXNRD1 and TXNRD3 were increased (P<0.05) in compound 2 group. In conclusion, these findings suggested that dietary addition of the compound Chinese herb ultrafine powder composed of motherwort, SM, LL and dandelion could enhance the anti-oxidative ability of laying hens during late laying period by increasing the activity of antioxidant enzymes in plasma and liver and activating liver antioxidant-related signaling pathways. In addition, these two compounds present target specificity for the regulation of anti-oxidative capacity in the body.

Key words: Chinese herb, ultrafine powder, laying hens, antioxidant properties, signaling pathway