Effects of fiber sources with different solubilities on the growth performance, nutrient metabolism, antioxidant, immune capacity and intestinal health of meat geese.

This study investigated the effects of dietary supplementation of indigenous dietary fiber (DF) sources with different solubilities on the growth performance, intestinal health, and gut microbiota in meat geese. A total of 400 meat geese at 17-d-old were randomly divided into 4 treatments with 10 replicates per treatment and 10 geese per replicate in a 28-d trial. The dietary treatments included a corn-soybean meal basal diet (BD), and BD supplemented with wheat bran as high soluble DF source (HS), alfalfa meal as medium soluble DF source (MS), or bamboo meal as low soluble DF source (LS). The results showed that dietary supplements of DF sources improved the growth performance of geese by improving final body weight (P = 0.010) and average daily weight gain (P = 0.003), and decreasing feed to gain ratio (P < 0.001). Among the DF source supplemented groups, HS treatment decreased the feed to gain ratio compared to LS treatment (P = 0.015). Next, HS and MS treatments decreased the levels of uric acid (P = 0.022) and triglyceride (P = 0.003) compared to BD and LS groups, and HS treatment decreased the high-density lipoprotein cholesterol level (P = 0.032) in serum compared to BD, LS, and MS groups. Additionally, dietary supplement of DF sources, especially the HS treatment improved the immune function of ileum and cecum by decreasing the levels of interlukin-10 level (P < 0.001) and interlukin-1β (P < 0.001), and increasing the level of secretory immunoglobulin A (P < 0.05) compared to BD, LS, and MS groups. Also DF sources supplements, especially the MS and HS treatments enhanced the antioxidant capacity of ileum and cecum by increasing activities of CAT (P < 0.001), SOD (P = 0.006 in ileum, P < 0.001 in cecum), and T-AOC (P < 0.001), but decreasing the MDA level (P < 0.001) compared to BD and LS groups. Furthermore, the length of ileum in BD group was shorter than DF source supplemented groups. And HS group had the longest ileum length (P = 0.010) and villus height (P = 0.001), and the most goblet cell number (P = 0.013) among all groups. Finally, by comparing the gut microbiota composition among BD, LS, and HS groups, HS treatment induced the enrichments of Butyricicoccus and Gemmiger, which were correlated with the improvements in the growth performance, lipid and fatty acid metabolisms, and intestinal condition. In conclusion, this study indicated that dietary supplementation of DF source, especially the high soluble DF source modulated the gut microbiota, enhanced the growth performance, nutrient metabolism, and intestinal health of meat geese. These findings suggested that highly soluble fiber sources might be preferable to use in geese production.