Dietary Supplementation with Fermented Radix astragalus-ginkgo Leaves Improves Antioxidant Capacity and Meat Quality in Broilers

The objective of this study was to compare the effect of non-fermented (NF) and fermented Radix astragali-ginkgo leaves (FR) products produced by fermentation using Aspergillus niger on growth, antioxidant capacity and meat quality of broilers. Three hundred day-old commercial Arbor Acres (AA) broiler chicks were randomly allocated into 5 dietary treatments including five variations: control group, fed with the basal diets; NF group, the addition of 3 g/kg NF products; FR1, FR2 and FR3 groups, addition of FR products 1 g/kg, 3 g/kg and 6 g/kg, respectively. There was no difference in body weight gain, feed intake and feed intake/gain ratio between treatments. Compared with the control group, the percentage of the abdominal fat, sarcous fat and lactic acid (LD) for FR groups were significantly decreased. Birds had significantly higher water holding capacity (WHC) when they were provided with the FR3 diet. Moreover, serum glutathione (GSH) and alpha-tocopherol (alpha-TOH) contents in the FR groups were increased, while, levels of total cholesterol (TC), malondialdehyde (MDA) in serum and hepatic reactive oxygen species (ROS) in FR groups were significantly decreased compared with the control or NF group at 42 d of age. Furthermore, serum total superoxide dismutase (T-SOD) activity of birds from group FR3 was significantly increased (42d) compared with NF group. Additionally, the expression of antioxidant enzyme genes including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), SOD, and glutathione peroxidase (GPx) were improved by FR supplemented into the broiler diets. Based on these results, FR could be acted as a beneficial feed additive with antioxidant capacity and meat quality-improving effect in broiler diets.