ABSTRACT
Background: Feed additives are products used in poultry nutrition to improve the quality of feed and the safety of food byproducts from animal origin. They are promising antibiotic alternatives for the production of broilers. Aim: This study aimed to investigate the effect of sodium butyrate (SB) and RL on growth performance, biochemical profile, immunity, and carcass traits of broilers. Methods: Five hundred-one-day-old chicks of the Hubbard breed were reared on floor pens in a privet farm, Giza. The chicks were weighed on arrival (each chick weighted 43-45 gm) and randomly assigned into five equal groups, with four replicates each (25 chicks/replicate). Group 1 was fed on a broiler diet without any additions (control). The diets of groups 2 and 3 were supplemented with 500 g/ton SB and 4 kg/ton RL, respectively. In group 4, the diet was enriched with 250 g/ton SB plus 2 kg/ton RL. Chicks in group 5 were fed on a diet fortified with 500 g/ton SB plus 4 kg/ton RL. Results: Supplementation of broiler diet with 500 g/ton SB plus 4 kg /ton RL increased body weight gain (BWG) and feed efficiency ratio (FER) of birds. It decreased serum levels of aspartate aminotransferase, alanine aminotransferase, total cholesterol triglycerides, and malondialdehyde, but increased superoxide dismutase, catalase, and immunoglobulins, phagocytic activity, lysozyme activity, and nitric oxide concentrations. Antibody titers against the Newcastle disease virus were also elevated. Conclusion: Supplementation of broiler diet with 500 g/ton SB plus 4 kg/ton RL gives the best result regarding productive efficiency and immunity of broiler chickens.
