Growth performance, carcass criteria, and serum biochemical parameters of broiler chickens supplemented with either synbiotic or prebiotic under hot climatic conditions.

1. Two separate experiments were conducted to evaluate the efficacy of either prebiotic or synbiotic on growth performance, carcass yield, organs weights, and serum metabolic profile of broilers under hot climatic conditions. 2. In experiment 1, one hundred and fifty 1-day old Ross 308 male broiler chickens were fed dietary synbiotic (Biomin® IMBO, 0, 1 or 1.5 g kg -1 of the starter diets and 0, 0.5 or 0.75 g kg -1 of the grower diets) for six weeks. In experiment 2, one hundred and fifty 1-day old Ross 308 male broiler chickens were fed dietary prebiotic (Mannan oligosaccharide 0 g, 0.5 or 1 g kg -1 of the starter diets and 0, 0.25 or 0.5 g kg -1 of the grower diets) for six weeks. Each treatment had ten replicates containing five broiler chickens each. 3. Supplementation of synbiotic at 1 or 1.5 g kg -1 feed to broiler diets during 1-21 days and 0.5 or 0.75 g kg -1 feed respectively, during 22-42 days improved (P<0.01) body weight gain, feed conversion ratio (FCR), and decreased (P<0.01) abdominal fat, serum total cholesterol, and low-density lipoprotein (LDL) cholesterol levels in experiment 1. 4. Similarly, supplementation of the prebiotic at 0.5 or 1 g kg -1 in broiler diets during 1-21 days and 0.25 or 0.50 g kg -1 feed respectively, during 22-42 days improved (P<0.01) body weight gain, FCR, and decreased (P<0.01) abdominal fat, serum cholesterol, and LDL cholesterol levels in experiment 2.