The present study investigated the effect of flaxseed grain or flaxseed oil on ileal microbiota and lipid deposition of cashmere goats. Sixty kid goats (average body weight 18.6 ± 0.1 kg) were allocated to three treatments, fed for 90 days, with control treatment: basal diet (CON, total-mixed ration), experimental treatment: basal diet with added flaxseed oil (LNO), experimental treatment: basal diet with added heated flaxseed grain (HLS). The final body weight, body weight gain, the weight of kidney fat, omental fat, tail fat, and fat tissue, the activity of fatty acid synthetase, acetyl-coa carboxylase, and malic dehydrogenase, and the relative abundance (RA) of unclassified_f_Peptostreptococcaceae and Intestinibacter were remarkably higher in the LNO treatment than in the HLS treatment, but the [Eubacterium]_coprostanoligenes_group RA showed the opposite result. The content of triglyceride, cholesterol, and low-density lipoprotein cholesterol were significantly higher in the CON and LNO treatments than in the HLS treatment, while the hormone-sensitive lipase activity and the non-esterified fatty acid content showed the opposite result. In conclusion, the flaxseed grain is more efficient than flaxseed oil in ameliorating the blood lipid profiles and it is a potential product for decreasing the lipid deposition of cashmere goats.

The present study investigated the effects of flaxseed oil or flaxseed grain on the intestinal microbiota and blood fatty acid profiles of Albas cashmere goats. Sixty kid goats were allocated to three treatments and fed for 90 days with a control treatment, comprising a basal diet (CON, total-mixed ration with flaxseed meal), or experimental treatments, comprising a basal diet with added flaxseed oil (LNO) and a basal diet with added heated flaxseed grain (HLS). On day 90, two goats were randomly selected from each pen (eight goats per treatment) for euthanizing; then, five of the eight goats were randomly selected, and we collected their intestinal (duodenum, jejunum, ileum, cecum, and colon) digesta for analysis of the bacteria community. The results indicated that Firmicutes are the most predominant phylum in different segments of the intestinal digesta. Compared with the CON group, the relative abundance of duodenal Firmicutes, jejunal Saccharibacteria, and Verrucomicrobia significantly decreased in the LNO and HLS groups (p < 0.05), but there was no significant difference between the LNO and HLS groups. Compared with the CON and HLS groups, the RA of duodenal and jejunal Proteobacteria remarkably increased in the LNO group (p < 0.05), and there was no significant difference between the CON and HLS groups. Compared with the CON and LNO groups, the RA of Actinobacteria remarkably increased in the small intestine of the HLS group (p < 0.05), but there was no significant difference between the CON and LNO groups in the duodenum and ileum. The results of linear discriminant analysis (LDA) effect size (LEfSe) analysis showed that the HLS group was characterized by a higher RA of the [Eubacterium]_coprostanoligenes_group in the small intestine and the LNO group was represented by a higher RA of the Lachnospiraceae_NK3A20_group in the cecum and colon, while the CON group was represented by a higher RA of Solobacterium, Pseudoramibacter, and Acetitomaculum in the small intestine and a higher RA of norank_o__Bradymonadales, the Prevotellaceae_Ga6A1_group, and Ruminiclostridium_1 in the cecum and colon. In conclusion, the addition of flaxseed oil and grain rich in c18:3n3 to the diet could reduce the microbial diversity of the small intestinal segments and the microbial diversity and richness of the cecum and colon in Albas cashmere goats. And flaxseed grain is more efficient than flaxseed oil in protecting intestinal health and promoting the absorption of c18:3n3.

This study investigated the effects of fermented and unfermented Astragalus straw on serum antioxidant status, lipid metabolism, and hormone profiles in lambs and explored the underlying mechanisms using 16S rRNA sequencing and untargeted metabolomics. Twenty-seven weaned lambs were randomly assigned to three groups: a control group fed a basal total mixed ration (CON), an unfermented Astragalus straw supplementation group (AM_S), and a fermented Astragalus straw supplementation group (FAM_S). The experiment consisted of a 15-day adaptation period followed by a 90-day feeding period. At the end of the trial, growth performance was evaluated and serum samples were collected. Six lambs from each group were randomly selected and euthanized for the collection of rumen fluid and liver tissues for omics analyses. Compared with the CON group, both the AM_S and FAM_S groups showed significantly improved growth performance (p < 0.05). Furthermore, glutathione peroxidase (GSH-Px) activity and Adipose triglyceride lipase (ATGL) levels were significantly increased, whereas Low-density lipoprotein cholesterol (LDL) levels, resistin, and insulin (INS) concentrations were significantly decreased in the supplemented groups (p < 0.05). Microbiota analysis revealed that g_norank_f_F082 and f_F082 were enriched in the CON group, g_UCG-009 and f_Butyricicoccaceae were enriched in the AM_S group, and f_norank_o_Clostridia_vadinBB60_group and o_Clostridia_vadinBB60_group were enriched in the FAM_S group (p < 0.05). Untargeted metabolomics analysis showed that differential metabolites in the AM_S group were enriched in the α-linolenic acid metabolism and vitamin digestion and absorption pathways in both serum and liver samples, with gluconolactone and 9-oxononanoic acid identified as key associated metabolites. Interestingly, metabolites associated with the neuroactive ligand–receptor interaction pathway showed distinct enrichment patterns between serum and liver samples in the FAM_S group, with adenosine and tryptamine identified as key associated metabolites. Correlation analysis further revealed significant associations among serum antioxidant indicators, lipid metabolism-related parameters, hormone levels, differential metabolites, and rumen microbial genera. In conclusion, supplementation with unfermented or fermented Astragalus straw improved antioxidant capacity (GSH-Px) and modulated lipid metabolism-related parameters (ATGL, LDL-C, resistin, and INS) in lambs. These changes were accompanied by alterations in rumen microbiota and serum metabolites, supporting the potential application of Astragalus straw as a functional feed ingredient for ruminants.