Effects of grape pomace supplementation to laying hen diet on performance, egg quality, egg lipid peroxidation and some biochemical parameters

This study was carried out to determine the effects of dried grape pomace supplementation in a corn-soy-based diet on performance, egg quality, plasma and egg lipid peroxidation, and some biochemical parameters of laying hens. In this study, 96 moulted 80-week-old Bovans laying hens were distributed into three groups with eight replicates. The hens were fed a supplemented diet with 0% (control group), 4% and 6% grape pomace (experimental groups) for 12 weeks. In the study, the effects of grape pomace supplementation in a corn-soy-based diet on performance, internal and external egg quality, serum total cholesterol, total protein, glucose and triglyceride levels, and plasma and egg yolk malondialdehyde (MDA) levels were determined. The addition of grape pomace to laying hen diet did not significantly affect live weight, feed intake, egg production and feed efficiency (P > 0.05). In all treatment groups, supplementation did not significantly affect albumen index, Haugh unit, egg yolk index, yolk colour, eggshell ratio, eggshell thickness, egg-specific gravity, total cholesterol, total protein and triglyceride compared to the control group (P > 0.05). In the study, 4% grape pomace supplementation to diet significantly increased egg weight (P < 0.001), and both 4% and 6% grape pomace supplementation levels significantly increased liver weight (P < 0.05) and liver weight ratio (P < 0.01). Grape pomace addition to laying hens diet significantly decreased plasma MDA and serum glucose levels (P < 0.001). Also, grape pomace addition significantly decreased egg yolk MDA levels on day 1 (incubation on 0 minute; P < 0.001), and day 15 [incubation on 0, 30, 60 and 90 (P < 0.05) minutes]. The results of this study concluded that performance, egg quality and serum total cholesterol, total protein and triglyceride levels were not negatively affected. Plasma and egg yolk MDA, and serum glucose levels were reduced by 4% and 6% supplementation to laying hen diets. It was concluded that grape pomace supplementation has the potential to extend shelf life.