Background: The prolonged cold season on the Qinghai-Tibet Plateau poses substantial challenges for most animals, including limited access to natural pasture, reduced appetite, and subsequent weight loss. The polysaccharides that are contained in yeast cell wall (YCW) act as prebiotics, promoting the action and development of beneficial gut microbiota while inhibiting the proliferation of pathogens, thereby maintaining normal gastrointestinal function in animals. Methods: This research aimed to examine how incorporating yeast cell wall (YCW) into the diet influences rumen fermentation, the composition of microbiota, and liver metabolism in Tibetan sheep. A total of 30 one-year-old Tibetan sheep, with an mean weight of 30.51 ± 7.07 kg, was randomly assigned to groups: a control group and a supplementation of 0.3% YCW group. Each group consisted of 15 sheep. The experimental period lasted for 98 days. Results: The research showed that the addition of YCW increased Dry matter digestibility and average daily gain (ADG) of Tibetan sheep significantly ( P < 0.05); the concentrations of propionic acid, acetic acid, total volatile fatty acids, and ammonia nitrogen in the rumen were significantly increased ( P < 0.05); In the liver, the mRNA expression of genes associated with gluconeogenesis, including Glucose-6-phosphatase, catalytic subunit (G6PC), Phosphoenolpyruvate carboxykinase 1(PEPCK1), and Fructose-1,6-bisphosphatase (FBP), were significantly increased following YCW supplementation ( P < 0.05); the mRNA expression level of Sterol regulatory element-binding protein 1c (SREBP1c), which is involved in lipid metabolism, was significantly decreased ( P < 0.05); The inclusion of YCW in the diet reduced the relative abundance of Desulfobacterota and Firmicutes significantly, and increased Prevotella ’s abundance significantly in the rumen ( P < 0.05). Liver metabolites were substantially enriched in the glycerolipid metabolism, glycolysis/gluconeogenesis, and the AMP-activated protein kinase (AMPK) signaling pathway ( P < 0.05). Conclusions: YCW supplementation in feed may advance the growth and gain of Tibetan sheep and improve gluconeogenesis. This effect may be ascribed to modifications in the rumen microbiota facilitating propionic acid fermentation, subsequently regulating liver lipid metabolism.

In this study, we examined whether dietary ADY improves growth, digestibility of feed nutrients, meat quality, and rumen microbial ecology in lambs. This experiment enrolled 90 healthy, similarly weighted (29.0 ± 0.5 kg) four-month-old Duhan lambs, which were randomly and evenly distributed into two treatment groups: a control group fed the basal diet and an ADY group fed the basal diet supplemented with 0.3 g/d per lamb of active dry yeast. The supplementation amount was adjusted weekly according to feed intake to maintain a constant daily dose. The results showed that, compared with the control group, ADY significantly increased the lambs’ average daily gain (ADG) and enhanced the apparent digestibility of neutral detergent fiber (NDF), crude protein (CP) (p < 0.05), and significantly reduced the feed conversion ratio (F/G) (p < 0.05). These improvements were accompanied by a shift in rumen fermentation toward propionate production, evidenced by higher NH₃-N, Total volatile fatty acids (TVFAs) and propionate proportion and a lower acetate proportion and acetate-to-propionate ratio (p < 0.05). ADY also altered the rumen microbiota, increasing Proteobacteria and Succinivibrionaceae_UCG-001 while decreasing norank_o_Clostridia_UCG-014 (p < 0.05). In muscle, ADY significantly increased the proportions of C14:0 and C18:3n-3 (p < 0.05). In addition, the proportion of C13:0, C18:0 and C18:2n-6t were significantly reduced (p < 0.05). In conclusion, dietary supplementation with ADY enhanced rumen fermentation, improved rumen microbial composition, and promoted nutrient utilization in lambs, thereby improving growth performance and meat quality. In addition, certain rumen microbial taxa may be associated with the formation of specific muscle fatty acids.

In this study, we investigated the effects of dietary supplementation with thermally modified attapulgite on the daily weight gain, serum biochemical indices, and serum metabolites of Simmental fattening cattle. A total of 30 healthy Simmental fattening beef calves of similar age (8 to 9 months old) and body weight (370 ± 10 kg) were randomly divided into two groups, each containing 15 animals. A control group was fed the basal diet, and a treatment group was fed the same basal diet with the addition of 4 g/kg of thermally modified attapulgite. After 75 days of formal experiment, the calves in the two groups were weighed, and blood samples were collected by tail vein blood sampling for determinations of the serum biochemical indices and serum metabolites using liquid chromatography–mass spectrometry (LC-MS) analysis. The results indicated that the addition of thermally modified attapulgite to the diet had no significant effects on the daily weight gain of fattening beef cattle. After feeding with modified attapulgite, the glutathione peroxidase and superoxide dismutase activities in the serum of the experimental group were 55.02% (257.26 U·mL⁻¹ to 165.95 U·mL⁻¹, p < 0.05) and 13.11% (18.98 U·mL⁻¹ to 16.78 U·mL⁻¹, p < 0.05) higher than that in the control group. Compared with the control group, the tumor necrosis factor-alpha content was reduced by 14.50% (31.27 pg·mL⁻¹ to 36.57 pg·mL⁻¹, p < 0.01), and the concentration of interleukin-6 and lipopolysaccharide decreased by 17.00% (34.33 pg·mL⁻¹ to 41.36 pg·mL⁻¹, p < 0.001) and 23.05% (51.34 EU·L⁻¹ to 66.72 EU·L⁻¹, p < 0.001) in the serum of the experimental group. Contrastingly, the thermally modified attapulgite had no significant effects on the levels of serum total protein, albumin, or globulin in Simmental fattening cattle (p > 0.05). Furthermore, the results of serum metabolomic analyses revealed that there were a total of 98 differential metabolites, which were mainly enriched with respect to glycerophospholipid metabolism, Th1 and Th2 cell differentiation, autophagy-other, retrograde endogenous cannabinoid signaling, and the NF-κB signaling pathway. Overall, thermally modified attapulgite was found to effectively increase the activity of antioxidant enzymes, reduce serum inflammatory mediators, may suppress oxidative damage, enhance immunity, and have a positive influence on the health of Simmental fattening beef calves.

This research explored how dietary supplementation of calcium nitrate influences methane emissions, nitrogen excretion, ruminal fermentation parameters, and microbiota in Liuyang black goats. A total of twelve male goats from this breed were divided into two groups: one serving as a control group (CON), while the other received a treatment of 3% calcium nitrate (CAL). The research was conducted over a period of 40 days and comprised two separate trial phases. A 10-day adaptation period and a 5-day sampling period (days 11–15) for each stage. Results showed that incorporating calcium nitrate significantly reduced the emissions of methane (CH₄) (p < 0.05) and carbon dioxide (CO₂) (p < 0.05). Moreover, the use of calcium nitrate modified the trends in ruminal fermentation, resulting in an increase in pH (p < 0.05). Moreover, the ratio of acetate to propionate (A:P) was notably reduced in the CAL group (p < 0.05), indicating a shift toward enhanced production of propionate. At the microbial level, an increased presence of Bacteroidota and Prevotella was observed in the CAL group (p < 0.05). In contrast, the CON group exhibited elevated levels of Firmicutes and Methanobrevibacter (p < 0.05). This finding suggests that calcium nitrate plays a significant role in reducing methane emissions and also affects the fermentation processes in the rumen along with the microbiota of Liuyang black goats. Further research is needed to examine the long-term implications of calcium nitrate supplementation on the health and productivity of these goats.