Abstract

The The use of Kaolin as an inert ingredient in feed has been very common in the poultry industry. The present study aimed to investigate the effects of different inclusion rates of Egyptian kaolinite in broiler chickens’ diet on growth performance, immune response, some blood serum changes, and bone development. A total of 240 unsexed one-day-old Avian 48 breed chickens were used in this experiment. The chickens were individually weighed and randomly allotted into 3 equal groups (80 chickens per each group) and each group was subdivided into 4 replicates (20 chickens per replicate), which received one of the three experimental diets (0.0, 0.5, and 1.0% kaolin for groups 1, 2, and 3, respectively) during the experimental period (6 weeks). The obtained data revealed that kaolin addition at the dose of 0.5 or 1.0% in broiler chickens' diet insignificantly increased final body weight by 4.5% and 4.4%, respectively. On the other hand, it respectively decreased total feed intake by 1.0% and 1.8% and significantly improved the average feed conversion ratio and efficiency of energy utilization throughout the whole experimental period compared to the control. Moreover, kaolin addition had no adverse effect on the serum lipid profile and improved antioxidative activity through reduced nitric oxide and lipid peroxidase (malondialdehyde) concentrations or increased the activities of Glutathione peroxide, Catalase, and Superoxide dismutases in serum or liver tissues. Lysosomal and bactericidal activities were increased with kaolin addition at both levels in the broiler chickens’ diets. The present results suggested that the broiler chickens’ fed with kaolin-enriched diets improved growth, antioxidant activity, bone mineralization, and immune response.