1. This study investigated the growth performance, caecal microbiota, blood chemistry, splenic cytokines, serum immunoglobulins, carcase, meat quality and oxidative status of broiler chickens fed diets supplemented with Anacardium occidentale leaf powder (AOLP) in comparison with antibiotic and synthetic antioxidant.2. Three hundred and twenty, one-day old Arbor Acre broiler chicks were randomly allotted into four treatment groups consisting of eight pen replicates with 10 birds per pen. The treatment groups were T0, basal diet only; T1, basal diet + 0.4 g/kg oxytetracycline + 0.12 g/kg butylated hydroxyanisole (BHA); T2, basal diet + 2 g/kg AOLP and T3, basal diet + 4 g/kg AOLP. The birds were fed for 42 d when performance was assessed, and then euthanised.3. During 0-42 d, feed conversion ratio was higher (P = 0.033) in T0 birds compared with birds fed other diets. Diet did not affect carcase traits, organ weights, serum biochemical indices, and meat composition, pH, cook loss or meat colour. Supplemented birds had higher erythrocyte (P = 0.042) and haemoglobin (P = 0.025), and lower leukocytes (P = 0.012) compared with the T0 birds.4. Diet T3 upregulated (P = 0.020) splenic interleukin-10 compared with other diets. The T0 birds had higher (P < 0.05) interleukin-6 and serum IgG and IgM compared with the supplemented birds. Caecal E. coli and Salmonella spp. counts were higher (P < 0.05) in T0 birds than in the supplemented groups. Lactobacillus spp. counts were higher (P = 0.001) in T3 birds than in those fed other diets. Breast and thigh meat from the T0 birds had higher (P < 0.05) TBARS value, and carbonyl content compared to the supplemented birds. The T0 breast meat had higher drip loss (P = 0.001) than meat from the supplemented birds.5. The results suggested that AOLP exhibited antimicrobial and antioxidant properties that were comparable to the responses to oxytetracycline and BHA (T1) in broiler diets. Nonetheless, the efficacy of AOLP needs to be verified under disease challenge or compromised health condition.
Keywords: Antibiotic; butylated hydroxyanisole; cytokine; immunoglobulin; spleen.