Pomegranate peel supplementation improves performance and lipid metabolism in laying hens

This study investigated the effects of dietary supplementation with pomegranate peel at various levels (0, 50, 100, and 150 mg kg^-1) in high-energy diets on the performance, egg quality, serum lipid profile, liver enzyme activity, and liver fat ratio of laying hens. A total of 120 Lohmann LSL laying hens, aged 70 weeks, were used in the study. The hens were divided into five experimental groups, each comprising six subgroups. The control group was fed a basal diet, while the treatment groups received high-energy (HE) diets supplemented with 0, 50, 100, or 150 mg kg^-1 pomegranate peel. During the 9-week trial, feed and water were provided ad libitum. Results indicated that supplementation with 150 mg kg^-1 pomegranate peel in the HE diet significantly improved egg production and the feed conversion ratio (FCR; $p<0.05$ ). Additionally, pomegranate peel supplementation had a positive effect on shell-breaking strength and yolk color. Triglyceride (TG) and very-low-density lipoprotein (VLDL) cholesterol concentrations were significantly reduced in the pomegranate peel supplemented groups compared to the HE $+$ 0 mg kg^-1 P group. Dietary supplementation with 100 and 150 mg kg^-1 pomegranate peel significantly ( $P<0.01$ ) reduced the liver fat ratio compared with the group fed the high-energy diet alone. Plasma malondialdehyde (MDA) and non-esterified fatty acid (NEFA) levels increased at 50 and 100 mg kg^-1 dietary pomegranate peel. In conclusion, it was found that the addition of pomegranate peel to a high-energy diet improved some performance and egg quality criteria and reduced the liver fat ratio. However, more detailed studies are required.