This study aimed to investigate the effects of fermented blueberry pomace (FBP) on the intestinal barrier function and cecal microbiome of aged laying hens. A total of 320 Yukou Jingfen No. 8 laying hens (345-day-old) were randomly divided into a control group, 0.25% FBP group, 0.5% FBP group, or 1.0% FBP group. The results showed that the villus height (VH) in the jejunum of the 0.25–0.5% FBP groups and villus surface area in the jejunum of the 0.25% FBP group were higher (p < 0.05), while 0.25% FBP supplementation displayed a higher (p = 0.070) VH in the ileum compared to the control group. Mucin-2 expression was upregulated (p < 0.05) in the jejunum of the 0.5% FBP group and the ileum of the 0.25–0.5% FBP groups. Compared to the control group, interleukin (IL)-4 and IL-13 expressions were upregulated (p < 0.05) in the 1.0% FBP group. Microbiota analysis revealed that Prevotella abundance in the cecum of the 0.5–1.0% FBP groups was higher (p < 0.05) than in the 0.25% FBP group. In addition, microbial function prediction analysis showed that cecal microbiota in the 0.25% FBP group were mainly enriched by alanine/aspartate/glutamate metabolism and methane metabolism. Moreover, Spearman’s correlation analysis revealed the potential correlations between the abundance of the cecal microbiota and intestinal-barrier-function-related gene expressions, as well as the short-chain fatty acid content, of laying hens. In summary, dietary FBP supplementation enhanced intestinal barrier function by improving intestinal morphology, upregulating gene expressions related to barrier function, and altering the cecal microbiota of aged laying hens.

This study aimed to evaluate the effects of fermented blueberry pomace (FBP) supplementation on carcass traits, meat quality, and antioxidant capacity in spent hens and further investigated underlying mechanisms using network pharmacology and molecular docking analyses. A total of 320 Yukou Jingfen No. 8 spent hens (345 days old) were fed a basal diet supplemented with 0, 0.25, 0.5, or 1.0% FBP for 56 days. Each group contained eight replicates with ten hens per replicate. Results showed that 0.25% FBP reduced the percentage of thigh muscle, whereas 0.5% FBP reduced drip loss at 24 h post-mortem in the breast muscle compared to the control group (p < 0.05). Additionally, 0.5% FBP enhanced the total antioxidant capacity compared to the 0.25% group and increased superoxide dismutase activity compared to the control and 0.25% FBP groups (p < 0.05). In the breast muscle, 0.25 and 0.5% FBP reduced drip loss compared to the control group at 48 h post-mortem, while 0.25% FBP upregulated glutathione peroxidase 1 expression more than the other groups (p < 0.05). Network pharmacology analysis identified 302 targets related to the potential bioactive compounds in FBP and 401 targets associated with meat quality, such as core targets of insulin, protein kinase cAMP-activated catalytic subunit beta, steroid receptor coactivator, etc. The identified key signaling pathways included JAK-STAT and PI3K-Akt signaling pathways, which were related to protein synthesis and muscle growth. Molecular docking analysis confirmed strong binding activity between bioactive compounds of FBP and meat quality. In conclusion, dietary FBP supplementation enhances the breast muscle quality of spent hens through the potential bioactive compounds targeting insulin and modulating JAK-STAT and PI3K-Akt signaling pathways, without affecting carcass traits. Moreover, 0.5% FBP exhibited better effects than other treatment groups in spent hens.

Strawberry pomace is a fruit processing by-product rich in fiber and bioactive compounds, making it a functional feed resource. This study evaluated the effects of fermented strawberry pomace (FSP) on laying performance, yolk fatty acid composition, ovarian function, intestinal barrier status, cecal microbiota, and short-chain fatty acids (SCFAs) in laying hens. A total of 320 laying hens (345-day-old) were assigned to diets containing 0, 0.25, 0.5, or 1.0% FSP for 8 weeks. Supplementing 0.25% FSP increased albumen height and Haugh unit (p < 0.05). In addition, 1.0% FSP reduced yolk saturated fatty acids and thrombogenic index and increased the polyunsaturated-to-saturated fatty acid ratio (p < 0.05). Dietary FSP supplementation enhanced reproductive endocrine activity by increasing plasma and ovarian hormones, whereas 0.25% FSP upregulated HSD17B1 and LHCGR expressions (p < 0.05). Dietary 1.0% FSP upregulated ovarian Nrf2 and SOD1 expressions, whereas 0.5% FSP improved small-intestinal morphology and upregulated intestinal barrier-associated gene expressions, including Occludin, Cadherin 1, and Mucin 2 (p < 0.05). Moreover, 0.5% FSP increased cecal microbial richness, reshaped microbial composition, and 0.25–1.0% FSP supplementation increased the molar proportion of acetic acid but decreased absolute acetic acid and total SCFAs concentrations (p < 0.05). In summary, dietary FSP improved yolk lipid nutritional quality, particularly at 1.0% supplementation. FSP supplementation also affected reproductive endocrine activity, intestinal barrier-related status, and cecal microbial fermentation.