This study aimed to investigate the effects of feeding high-moisture corn (HMC) on weight performance, serum immune and antioxidant indices, rumen fermentation, microbial community, and metabolomics in Kazakh rams. A total of 32 healthy Kazakh rams were randomly divided into a control group (CT, diet with only ordinary crushed corn) and an experimental group (GS, diet with 50% ordinary crushed corn + 50% HMC), following a 7-day adaptation period and a 120-day trial period. Results showed that the F/G was significantly lower in the GS group than in the CT group (p < 0.05). FBW, net weight gain and ADG increased by 4.58%, 8.69%, and 8.70%, respectively, while ADFI decreased by 7.04% (p > 0.05). Regarding serum immune indices, IgA in the GS group was significantly higher at 40 d (p < 0.01), and IgM was significantly higher at 40, 80, and 120 d (p < 0.05). For antioxidant indices, the SOD activity in the GS group was significantly higher than that in the CT group at 120 d (p < 0.01). The CAT activity in the GS group was significantly higher at 40, 80, and 120 d (p < 0.01). Among rumen fermentation parameters, the concentration of butyric acid in the GS group was significantly lower than in the CT group (p < 0.01). Microbial diversity analysis indicated no significant differences in Alpha- and Beta-diversity of rumen microorganisms between the two groups. However, the relative abundance of Firmicutes_A at the phylum level was significantly higher in the GS group (p < 0.05), and the abundance of Cryptobacteroides was significantly higher than in the CT group (p < 0.01). Rumen metabolomic analysis identified a total of 1357 differential metabolites, among which 1130 showed significant differences, with 459 upregulated and 671 downregulated. These were mainly enriched in pathways such as Glutathione metabolism, Beta-alanine metabolism, Sphingolipid metabolism, and lysine degradation. In conclusion, feeding HMC can improve feed conversion efficiency and weight performance in Kazakh rams, regulate the structure of dominant rumen microorganisms, and enhance immune and antioxidant capacities.

Grapevine branch and leaf silage (GBLS), a polyphenol-rich unconventional forage, exhibits antimicrobial and antioxidant properties that can benefit animal health and productivity. A total of 60 healthy six-month-old Kazakh rams (43.29 ± 4.55 kg, p > 0.05 for initial body weight among groups) were randomly assigned to three dietary groups, each consisting of four replicates with five rams per replicate. The control group (CK) was fed a basal diet based on whole-plant corn silage, whereas the experimental groups received diets in which 50% (GBLS50%) or 100% (GBLS100%) of the corn silage was replaced with GBLS. A 10-day adaptation period preceded the 90-day formal feeding trial. Results showed a significant quadratic response for average daily gain (ADG) and average daily feed intake (ADFI) across GBLS substitution rates (p < 0.05), with the 50% level yielding the highest values. Specifically, ADFI at the 50% replacement level was significantly higher than that of the control (p < 0.05), confirming an inverted U-shaped response with 50% as the optimal substitution rate. However, in-depth analysis of serum biochemical parameters revealed that GBLS supplementation significantly reduced serum concentrations of total cholesterol, triglycerides, urea nitrogen, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA), while significantly increasing levels of immunoglobulins (IgA, IgM, IgG), superoxide dismutase (SOD), and catalase (CAT) (p < 0.05). Rumen fermentation analysis showed that the GBLS50% group had significantly lower concentrations of acetate, butyrate, and total volatile fatty acids (VFA) (p < 0.05). In the rumen microbiota study, no significant differences were observed in alpha or beta diversity or at the phylum level between groups (p > 0.05); however, the abundance of Lactobacillus gasseri was significantly reduced in the GBLS50% group (p < 0.05). Metabolomic profiling identified 43 significantly altered metabolites—27 upregulated (e.g., PE (18:1(9Z)/0:0) and 12,14-pentacosadiynoic acid) and 16 downregulated (e.g., deoxyadenosine). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis highlighted purine metabolism as a significantly altered pathway (p < 0.05), providing insight into the potential metabolic mechanisms underlying the physiological effects of GBLS in rams. In conclusion, replacing 50% of whole-plant corn silage with grapevine branch and leaf silage improves growth performance trends and significantly enhances immunity and antioxidant capacity in Kazakh rams.

This study investigated the effects of feeding High-Moisture Corn (HMC) on meat production performance, mutton quality, muscle metabolism, and gut microbiota in Kazakh rams. Thirty-two 6-month-old Kazakh rams were divided into a control group (CT) and an experimental group (GS). Both groups received a basal diet consisting of 30% whole-plant corn silage, 30% cotton residue, and a concentrate mixture. In the CT group, the concentrate contained 24% ordinary crushed corn (on a dry matter basis). In the GS group, half of the ordinary crushed corn was replaced with HMC, resulting in a concentrate containing 12% ordinary crushed corn and 12% HMC. After a 120-day feeding period, backfat thickness was significantly higher in the GS group (p < 0.05); For meat quality, muscle shear force was significantly lower (p < 0.01) and intramuscular fat content was significantly higher (p < 0.01) in the GS group; Amino acid analysis showed that aspartic acid content was significantly lower (p < 0.01), arginine and glutamine contents were significantly lower (p < 0.05), and glycine content was significantly higher (p < 0.05) in the GS group; Fatty acid analysis revealed that the contents of methyl undecanoate, methyl myristate, methyl palmitate, methyl heptadecanoate, methyl alpha-linolenate, and all-cis-4,7,10,13,16-docosapentaenoic acid were significantly higher in the GS group (p < 0.01), while the contents of ten other fatty acids, including methyl caprate, methyl laurate, and methyl tridecanoate, were significantly higher (p < 0.05); A total of 668 metabolites were detected by muscle metabolomics, and 20 of them were identified as significantly differential metabolites, with the GS group showing 15 upregulated and 5 downregulated, mainly enriched in four pathways: valine, leucine and isoleucine biosynthesis; taurine and hypotaurine metabolism; pantothenate and CoA biosynthesis; and the citrate cycle (TCA cycle); Gut microbiota analysis showed no significant difference in alpha diversity, but beta diversity was significantly separated between the two groups (p < 0.01); Correlation analysis revealed that Firmicutes_A was significantly negatively correlated with most fatty acids, while Proteobacteria was significantly positively correlated with multiple fatty acids (p < 0.05). In conclusion, The GS group had significantly increased backfat thickness, reduced muscle shear force, increased intramuscular fat content, and significantly enriched beneficial fatty acids in Kazakh rams, thereby improving meat quality.

With the continuous development of the livestock industry, the availability of high-quality roughage is becoming increasingly constrained. Therefore, the exploitation of unconventional feed resources is crucial for the sustainable development of the sector. Grape branches and leaves are a major by-product of viticulture, abundant in supply but currently underutilised. Their ensilage presents potential feed value and ecological benefits. This study aimed to systematically evaluate the effects of dietary supplementation with grape branch and leaf silage on the growth performance, serum biochemical parameters, gut microbiota, and metabolomic profiles of Kazakh rams. Sixty Kazakh rams aged 6.0 ± 0.5 months with similar initial body weight (34.21 ± 2.13 kg) were randomly allocated to three dietary treatment groups: the control group (CG) fed whole-crop corn silage, the EG50 group where grape branch and leaf silage replaced 50% of the whole-crop corn silage, and the EG100 group where grape branch and leaf silage entirely replaced the whole-crop corn silage. Each treatment comprised four replicates with five rams per replicate. Following a 7-day adaptation period, a formal feeding trial was conducted for 120 days, after which relevant parameters were measured. Results: (1) Compared with the CG, the dressing percentage was significantly increased in the EG100 group (p < 0.05), while tail fat weight and tail fat percentage were both markedly decreased (p < 0.01). (2) Serum immunoglobulin (IgA, IgG) levels and antioxidant enzyme (SOD, CAT) activities were significantly elevated in the EG100 group (p < 0.05), accompanied by enhanced total antioxidant capacity. Concurrently, levels of inflammatory cytokines (IL-1β, TNF-α) and the oxidative damage marker malondialdehyde (MDA) were significantly reduced (p < 0.05). (3) Based on slaughter performance, jejunal microbiota analysis was performed for the CG and EG100 groups. The relative abundance of the phylum Firmicutes increased in the EG100 group, with beneficial genera such as Ruminococcus and Lactobacillus becoming predominant. (4) Metabolomic analysis revealed significant enrichment of pathways including primary bile acid biosynthesis and glycerophospholipid metabolism in the EG100 group, with 20 key differential metabolites identified. Dietary supplementation with grape branch and leaf silage may improve slaughter performance and reduce fat deposition in Kazakh rams, potentially by modulating the gut microbiota structure and its metabolic functions, thereby synergistically enhancing nutrient utilisation, anti-inflammatory capacity, and antioxidant status. This study provides a theoretical basis for the feed-oriented and value-added utilisation of grape processing by-products. Future research should further elucidate the molecular mechanisms underlying the interaction between its active components and host metabolism.