Abstract
The present study aimed to investigate the effects of dietary supplementation with powdered peanut skin (PS) as natural antioxidant and growth promoter on growth performance, carcass characteristics, serum metabolites and meat quality of Cobb broiler chickens. A total of 240 unsexed Cobb 500 1-week-old broiler chicks were randomly assigned to four treatment groups with six replicates. The dietary treatments consisted of the basal diet as control and PS groups (1.0, 2.0, and 3.0 PS g/kg). Results showed that the highest values (P < 0.01) of live bodyweight and bodyweight gain were observed in the control group at 3 weeks of age and during the period of 1-3 weeks of age, respectively compared with all levels of PS. During 1-3 weeks of age, feed intake per day chicks fed the diet containing PS levels decreased numerically (P> 0.01) with increased levels of PS compared with the control. Supplementing 1.0 or 3.0 g/kg of PS insignificantly enhanced feed conversion ratio at 1-6 weeks of age. Dietary treatments significantly depressed giblets (P = 0.002), thigh (P = 0.0.027) and abdominal fat percentages (P> 0.0.1), however, increased (P= 0.004) breast percentage of broiler chicks at 6 weeks of age. The lowest value of serum creatinine and urea achieved by chicks fed diet contained 3.0 PS g/kg diet. Also, high density lipoprotein cholesterol in addition to triglycerides were significantly (P < 0.05 and P < 0.01) decreased with increasing level of PS supplementation. It can be concluded that PS as a phytogenic additive could be used as a supplementation to broiler diets to lower abdominal fat in carcass and cholesterol, creatinin and urea in blood. Sensory characteristics were not affected except that appearance was improved. Water-holding capacity was also improved.