Effects of Fucoidan on Rumen Microflora and Metabolomics of Weaned Lambs

Abstract

This experiment was conducted to investigate the effects of fucoidan on rumen microflora and metabolomics of weaned lambs. Sixty healthy 60⁃day⁃old weaned lambs (Chuanzhong black goat) with similar body weight of (12.5±0.5) kg were randomly divided into 4 groups with 15 lambs in each group. Lambs in control group (CON group) were fed a basal diet, and others in experimental groups were fed the basal diet supplemented with 0.1% (F1 group), 0.3% (F2 group) and 0.5% (F3 group) fucoidan, respectively. The re⁃experimental period lasted for 7 days, and the experimental period lasted for 30 days. The results showed as follows: 1) compared with the CON group, the final weight, average daily gain and average daily feed intake of F2 and F3 groups were significantly increased (P < 0. 05), and the feed to gain ratio of F1, F2 and F3 groups was significantly decreased (P<0.05) . 2) Compared with the CON group, the rumen pH and of acetic acid, butyric acid and isobutyric acid contents and acetic acid / propionic acid of F1, F2 and F3 groups were significantly increased (P<0.05), and the rumen propionic acid content of F2 and F3 groups was significantly increased (P<0.05) . 3) At phyla levels, compared with the CON group, the rumen Verrucomicrobia relative abundance of F1, F2 and F3 groups was significantly increased (P<0.05); the rumen Bacteroidetes relative a⁃ bundance of F1 and F3 groups was significantly increased (P<0.05), and the Actinobacteria, Euryarchaeota and Spirochaetes relative abundances were significantly decreased (P<0.05) . At genera levels, compared with the CON group, the relative abundances of unspecified_BS11, unspecified_RF16 and unspecified_S24_7 in rumen of F1 and F3 groups were significantly increased (P<0.05), and the unspecified_Lachnospiraceaea and unspecified_Veillonellaceae were significantly decreased (P<0.05) . 4) The metabolomics results showed that in the positive ion mode, compared with the CON group, the rumen metabolite contents of carbohydrates, pep⁃ tides, nucleic acids and hormones and transmitters of F1, F2 and F3 groups were significantly decreased (P< 0.05), and the metabolite contents of organic acids, vitamins and cofactors, steroids and lipids were signifi⁃ cantly increased (P<0.05) . In the negative ion mode, compared with the CON group, the rumen metabolite contents of steroids and hormones and transmitters of F1, F2 and F3 groups were significantly decreased (P< 0.05), and other metabolite contents were significantly increased (P<0.05) . It is concluded that the fucoidan can improve the rumen fermentation and rumen microbial flora diversity and relative abundance of weaned lambs, and affect the rumen metabolites and metabolic pathways.