Effects of Dietary Pomegranate Syrup Supplementation on Growth Performance, Carcass Traits, Meat Quality, Oxidative Stress, and GPx7 Gene Expression in Japanese Quail (Coturnix coturnix japonica)

The aim of this study was to evaluate the effects of pomegranate syrup supplementation at levels of 0.0%, 0.1%, 0.2%, and 0.3% in the diets of quail (Coturnix coturnix japonica) on performance parameters, including body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), hot and cold carcass weights and carcass yields; meat quality characteristics, including L*, a*, b* color values, pH, and water-holding capacity (WHC) of breast and thigh meat; and oxidative stress parameters, including total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI); as well as glutathione peroxidase (GPx7) gene expression. A total of 120 newly hatched quail chicks were used in the experiment. The birds were assigned according to a completely randomized design with 15 replicates per treatment group and 2 birds per replicate and were randomly distributed into 60 cage compartments. While cumulative body weight gain (CBWG) was not significantly affected during the other experimental weeks (p > 0.05), statistically significant differences among the groups were observed only in the second week (p < 0.05). Feed intake values were not significantly different among the groups throughout all weeks of the experiment (p > 0.05). However, feed conversion ratio (FCR) was significantly different among the groups during all weeks (p < 0.05), with the pomegranate syrup-supplemented groups generally showing improved (lower) values compared with the control group. The inclusion of pomegranate syrup in the diets did not produce significant differences among the groups in breast meat quality parameters, including color values (L*, a*, b*), pH, and water-holding capacity. The obtained L*, a*, b*, and pH values were within the reference ranges reported in the literature. Evaluation of oxidative stress parameters demonstrated that pomegranate syrup supplementation increased TAS values, while significantly reducing TOS and OSI values (p < 0.05). Furthermore, GPx7 gene expression increased in the pomegranate syrup-supplemented groups compared with the control group, with the highest expression observed at the 0.1% supplementation level. In addition, toxicological evaluations have confirmed the safety of pomegranate preparations, further supporting their potential as feed additives.