Abstract
Plant extracts have been proved as natural antioxidants resources as well as alternative feed additives in livestock and poultry species. Chestnut wood extract (CWE) as a source of hydrolysable tannic acid was used to evaluate the growth performance, nutrient retention, meat quality, antioxidant status, and immune function of broilers. A total of 168, day-old Arbor Acre male broilers (weight 46.59 ± 0.44 g) were randomly divided to 3 treatments, 7 replicate pens per treatment, 8 broilers per pen. The treatments contain a control diet, CON (corn-soybean meal basal diet); an antibiotic diet, CTC (basal diet + 75 mg/kg chlortetracycline); and chestnut wood extract diet, CWE (basal diet + 1,000 mg/kg chestnut tannins). At the finisher phase, final body weight was higher (P < 0.05) in CWE supplemented diet than in CON. Average daily body weight gain was higher (P < 0.05) and feed gain ratio was lower (P < 0.05) in broilers fed CWE than in those fed CON at the finisher phase. Crude protein digestibility was higher (P < 0.05) in broilers offered CWE than that in broilers fed CON and CTC diets. Breast muscle pH value at 24 h (pH(24 h)) was higher (P < 0.05) in broilers fed CWE than that in those fed CON and CTC diets. The bursa weight was higher (P < 0.05) in broilers offered CWE than that in those fed CON and CTC. Total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) values were higher (P < 0.05) in both breast muscle and thigh muscle of broilers offered CWE supplemented diet than those in broilers fed CON and CTC diets. Similarly, broilers offered with CWE diets showed higher (P < 0.05) T-AOC, GSH-PX, and SOD value in serum than those fed CON and CTC diets. Serum concentration of IgG was higher (P < 0.05) in broilers offered with CWE diets than that in those fed CON and CTC diets. Total cholesterol, low-density lipoprotein cholesterol, and urea-N concentration were lower (P < 0.05) in broilers offered CWE diet than those in broilers fed CON and CTC diets. It was recommended to supply CWE at the 1,000 mg/kg level for improving antioxidant status, cholesterol metabolism, and growth performance without affecting normal meat quality in broilers.