PSVI-2 - Effects of natural capsicum extract as a substitute for chlortetracycline on growth performance, nutrient utilization, antioxidant status, immune function, and meat quality in broilers

A total of 168 one-day old broilers (average BW 46.4 ± 0.6 g) were selected to determine effects of natural capsaicin extract (NCE) as a substitute for chlortetracycline (CTC) on performance, antioxidant capacity, immune function and meat quality of broilers [Founded by NSFC (31772612)]. Broilers were randomly allotted into 3 dietary treatments (n = 7) including a corn-soybean meal basal diet (CON), a basal diet + 75 mg/kg CTC (CTC), and a basal diet + 80 mg/kg NCE (NCE). The experiment contained phase 1 (day 1 to 21) and 2 (day 22 to 42). Compared with CON, broilers from NCE showed higher average daily gain at all stages (P < 0.05). On day 42, organic matter, crude protein and gross energy digestibilities of broilers from NCE were higher than those from the other two groups (P < 0.05). Higher percentage of bursa of Fabricius was observed in broilers fed NCE diets compared with CON (P < 0.05). Trypsin and lipase activities in the pancreas of broilers from NCE were higher than those from CON (P < 0.05). Breast muscle of broilers fed NCE diets showed lower L* values compared with CON (P < 0.05). Broilers from NCE also showed higher levels of serum total antioxidant capacity, glutathione peroxidase, superoxide dismutase, lower levels of interleukin-1β and tumor necrosis factor-α compared with broilers offered CON diets (P < 0.05). Compared with CON, lower concentrations of serum urea-N, low-density lipoprotein cholesterol and total cholesterol, higher growth hormone level were observed in broilers fed NCE diets (P < 0.05). In conclusion, supplementing 80 mg/kg of NCE to diets could improve growth performance, nutrient digestibility, antioxidant and immune function, and meat quality of broilers. Moreover, broilers fed NCE diets exhibited similar growth performance and health status to those offered chlortetracycline (CTC) diets.