Effect of different doses of fermented Ginkgo biloba leaves on serum biochemistry, antioxidant capacity hepatic gene expression in broilers

The current study was carried out to determine the influence of supplemental fermented Ginkgo biloba leaves (FGBL) at different levels on serum biochemistry and antioxidant capacity in broilers. A total of 648 one-d-old broiler chickens were randomly allocated into six dietary treatments, including control group (basal diet), FGBL1, FGBL2, FGBL3, FGBL4 and FGBL5 groups (basal diet containing 1.5, 2.5, 3.5, 4.5 and 5.5 g/kg FGBL, respectively). The experiment lasted for 6 weeks. At 42 d, 2 birds with nearly equal body weight from each replicate were slaughtered. The results indicated that gain to feed ratio had linear and quadratic influences by FGBL addition. The activity of glutathione peroxidase (GSH-PX) in serum, total antioxidant capability and total superoxide dismutase activities in liver and nuclear hepatic transcription factor erythroid 2-related factor mRNA expression followed the same fashion. The supplementation of FGBL linearly increased serum albumin concentration and hepatic GSH-PX mRNA expression, linearly decreased serum triglycerides concentration, malondialdehyde concentration in both serum and liver. There were quadratic influences on body weight and serum total protein concentration as supplemental FGBL level increased. Finally, it can be summarized that addition of FGBL affected growth performance, serum biochemistry and antioxidant capacity of broiler chickens. The optimal dose in the present study of FGBL in broiler diets was from 3.5 to 4.5 g/kg.