Neonatal calves’ diarrhea, which can be severe enough to cause death, has a significant impact on the global cattle industry. In this study, alfalfa polysaccharides and seaweed polysaccharides were found to significantly improve the diarrhea condition in neonatal calves. To explore the underlying mechanisms, further microbiomic and metabolomic analyses were conducted. This study investigated the impact of alfalfa polysaccharides and seaweed polysaccharides on growth performance, serum metabolites, gut microbiota, and metabolomics in neonatal Holstein calves. A total of 24 newborn calves were randomly assigned to three groups, with 8 calves per treatment group. The control (CON) group was fed a basal diet, the alfalfa polysaccharide (AP) group received a basal diet supplemented with alfalfa polysaccharides (4 g/calf/day), and the seaweed polysaccharide group (SP) received a basal diet supplemented with seaweed polysaccharides (4 g/calf/day). These polysaccharides were plant extracts. Compared to the CON group, the results indicated that SP significantly enhanced the body weight, height, chest circumference, and average daily gain of Holstein calves (p < 0.05), while also reducing the diarrhea rate and improving manure scoring (p < 0.05). Compared to the CON, AP also reduced the diarrhea rate (p < 0.05). In terms of serum biochemistry, supplementation with AP and SP increased serum alkaline phosphatase (ALP) and insulin-like growth factor 1 (IGF-1) levels compared to the CON group (p < 0.05). Both AP and SP elevated serum catalase (CAT) and Total Antioxidant Capacity (T-AOC) levels, indicating enhanced antioxidant status (p < 0.05). Regarding immune responses, supplementation with AP and SP significantly increased serum complement component 3 (C3) and immunoglobulin M (IgM) levels, while significantly reducing pro-inflammatory cytokines interleukin-18 (IL-18), tumor necrosis factor alpha (TNF-α), and interferon-gamma (IFN-γ) compared to the CON group (p < 0.05). Microbiota analysis revealed that AP modulated the abundance of Firmicutes, while SP influenced the abundance of Prevotella and Succiniclasticum. AP and SP differentially influenced intestinal metabolites compared to the CON group, leading to enrichment in pathways related to immunity, antibacterial, and anti-inflammatory functions. These pathways included the biosynthesis of alkaloids from ornithine, lysine, and nicotinic acid, glucocorticoid and mineralocorticoid receptor canothersis/antagonists, secondary metabolite biosynthesis, and alkaloid biosynthesis from histidine and purine, thus alleviating intestinal inflammation. Therefore, by supplementing with AP and SP, the diarrhea rate in calves was reduced, and the immune function of Holstein calves was enhanced, while simultaneously promoting a higher relative abundance of beneficial gut bacteria and suppressing the relative abundance of pathogenic bacteria. Additionally, gut pathways associated with immune response and inflammation were modulated by AP and SP. This study provided valuable insights and theoretical underpinnings for the use of AP and SP in preventing diarrhea in neonatal calves.

Objective: The study aimed to compare the growth performance, rumen fermentation, and rumen bacterial community of fattening Hu sheep fed either total mixed ration (TMR) or pelleted total mixed ration (PTMR) and to assess the feeding efficiency.Methods: In a 58-day feeding experiment, forty-eight Hu sheep were randomly assigned to two groups (TMR and PTMR), with six pens per group and four sheep per pen. Body weight and feed intake were measured throughout the experiment to assess growth performance. On the final day of the experiment, rumen fluid was collected from sheep using a rumen fluid collector two hours post-feeding.Results: The sheep in the PTMR group exhibited significantly higher body weight (p<0.05) and average daily gain (p0.05). No statistically significant differences were observed in rumen fermentation parameters between the TMR and PTMR groups. However, analysis of rumen bacteria revealed that the Sob, Ace, Bootstrap, Shannon, and Chao indices were significantly lower in the PTMR group compared to the TMR group (p<0.05). Bacteroidetes and Firmicutes were the predominant bacteria in all groups, with the abundance of Succinivibrionaceae_UCG-001 significantly lower in the PTMR group. The relative abundance of Rikenellaceae_RC9_gut_group, NK4A214_group, and Streptococcus was significantly higher in the TMR group than in the PTMR group (p<0.05). Bacterial function prediction showed downregulation of the energy production and conversion pathway in the PTMR group (p<0.05). Correlation analysis indicated that norank_f_Bacteroidales_RF16 positively correlated with butyric acid (p<0.05), while Anaerovibrio negatively correlated with acetic acid, propionic acid, butyric acid, and total volatile fatty acids (p<0.05).Conclusion: In summary, the results demonstrate that PTMR significantly enhances average daily gain in Hu sheep while maintaining rumen fermentation parameters, although accompanied by modifications in rumen bacterial community structure.

Objective: This study aimed to develop a novel extruded compound feed, characterize its rumen degradation parameters, and investigate the effects on growth performance, diet digestibility, rumen fermentation, and bacterial community of fattening cattle.Methods: To determine the optimal ratio, we measured key nutritional components and ruminal degradability using in situ nylon bag technology. Subsequently, 36 fattening cattle (618.0±23.3 kg) were randomly assigned to the control group (CON) and the extruded compound feed group (EXP), with 18 cattle per group. The feeding experiment lasted 60 d.Results: With the increase in corn percentage in the extruded compound feed, the effective degradability of neutral detergent fiber (NDF) increased (p = 0.056). At the ratio of peanut vine: corn: urea of 65:30:5, the effective degradability of NDF reached the highest value of 27.3%. This extruded compound feed was used in the subsequent feeding experiment. The EXP group had higher average daily feed intake (CON vs. EXP: 16.0 kg vs. 17.2 kg, respectively, p<0.001) and average daily gain (CON vs. EXP: 1.51 kg vs. 1.72 kg, respectively, p<0.001). The feeding profit per head of fattening cattle in the EXP group was 7.1 US dollars higher than that in the CON group. The 16S rRNA sequencing results showed that the relative abundance of Bacteroidetes (CON vs. EXP: 37.7% vs. 59.2%, respectively, p<0.001) and Prevotella_1 (CON vs. EXP: 16.0% vs. 36.1%, respectively, p<0.001) in the rumen of cattle fed the extruded compound feed was increased.Conclusion: These results revealed that the optimal ratio of peanut vine: corn: urea was 65:30:5, representing the most efficient and cost-effective composition. The extruded compound feed is a promising feedstuff, that can significantly enhance rumen fermentation and growth performance in fattening cattle.