Fermented blueberry pomace supplementation improves egg quality, liver synthesis, and ovary antioxidant capacity of laying hens

The present study aimed to investigate the effects of dietary fermented blueberry pomace (FBP) supplementation on production performance, egg quality and nutritional value, plasma biochemical parameters, follicle number, reproductive hormones, lipid metabolism, and antioxidant capacity of laying hens during the late laying period. A total of 320 (345-d-old) Yukou Jingfen No. 8 laying hens were randomly divided into 4 groups, with eight replicates per group and 10 hens per replicate. The birds were fed a basal diet (control group) and a basal diet supplemented with 0.25, 0.5, and 1.0% FBP. The trial lasted 56 d. The results showed that FBP (0.25-1.0%) supplementation increased the egg albumen height and Haugh unit compared with the control group on d 14, while 0.5 to 1.0% FBP increased the eggshell thickness compared with the 0.25% FBP group on d 28 of the trial (P < 0.05). The methionine content in egg white was higher (P < 0.05) in the 1.0% FBP group compared with the 0.25% FBP group. The CAT activity in the ovary was increased (P < 0.05) in the FBP groups compared with the control group, while plasma GSH-PX activity was higher (P < 0.05) in the 1.0% FBP group compared with the 0.25% FBP and 0.5% FBP groups. Dietary FBP supplementation up-regulated (P < 0.05) gene expressions related to lipid metabolism in the liver (ACC, FAS, SCD1, and SREBP1) and yolk precursor synthesis (ESR2 and VTG II). Moreover, CYP11A1 expression in the ovary was up-regulated (P < 0.05) in the FBP groups compared with the control group, as well as in the 0.25% FBP group compared with the 1.0% FBP group. In summary, dietary FBP supplementation improved egg quality and nutritional value, ovarian antioxidant capacity, and yolk precursor synthesis, while 1.0% FBP had better effects than 0.25 and 0.5% doses.