Effect of stocking density and supplementation of potato peel (Solanum tuberosum L.) powder and extract on the physiological and immunological performance of Japanese quail, Coturnix coturnix japonica

This study aimed to investigate the effects of stocking density and supplementation of potato peel (Solanum tuberosum L.) powder and extract on Japanese quail s physiological and immunological performance. A total of 810 quail chicks were randomly assigned to six dietary treatments and two stocking densities in a complete randomized design with a 6×2 factorial scheme. The quail were kept with a stocking density of 333cm²/birds (15 birds/replicate), and 167cm²/birds (30 birds/replicate). The first treatment served as a control diet without supplementation (T1). T2 and T3 were supplemented with potato peel extract (PPE) at 15, and 30ml/l in drinking water; T4, T5 with 15, and 30g/kg potato peel powder (PPP) in basal diet, and T6 with PPE at 15m/l+PPP at 15g/kg. A significant improvement in WBC (T2 and T6), total protein and globulin, and a significant decrease in relative weight of spleen in T3 and T6, bursa of fabricus and bursa index in all treatments, albumin in T2 and T3, glucose, and cholesterol were observed compared to control. Immune response, and value of antibodies titer against Newcastle and Gumboro disease were significantly better than control. In conclusion, the supplementation of PPE, PPP and their mixture showed the best physiological and immune response. Furthermore, the low density performed better in most studied traits.