Effect of propolis supplementation and breed on growth performance, immunity, blood parameters and cecal microbiota in growing rabbits

Abstract

Objective: The present study was conducted to investigate the potential effects of dietary supplemented propolis in two growing rabbit breeds on growth performance, immune response, blood parameters, carcass characteristics, and cecal microflora composition.Methods: A total of 90 growing rabbits aged 6 weeks from two breeds (V-line and Jabali) were randomly allocated to 3 dietary propolis experimental treatments. The experimental treatments consisted of a 2×3 factorial arrangement with two rabbit breeds and three levels of dietary propolis supplementation (0, 250 mg/kg, and 500 mg/kg). Each sub-treatment has 15 rabbits. The experimental period lasted six weeks.Results: There were no significant differences in growth performance and carcass characteristics due to propolis administration. Propolis supplementation at a high level significantly increased (linear; p<0.05) cellular-mediated immunity compared with the unsupplemented group. Furthermore, the rabbits receiving propolis exhibited a significant increase (linear and quadratic; p<0.03) in IgM immunoglobulins compared to the control. The current study provides further evidence that the dietary inclusion of propolis can significantly reduce pathogenic bacterial colonization in growing rabbits. The total count of microflora, E. coli, and Salmonella spp. was significantly lower (linear; p<0.01) in supplemented rabbit groups compared to the control group according to the microbiological analysis of cecal digesta. Based on breed effect, the results indicated that Jabali rabbits (local) performed better than V-line rabbits (foreign) in the majority of the studied traits.Conclusion: Dietary propolis is promising for further investigation into improving intestinal health and enhancing immunity in growing rabbits.