Lingyan Li

Objective: This study was conducted to evaluate the effects of supplementation strategies containing rumen-protected glucose (RPG) on growth performance, colonic fermentation characteristics, bacterial community structure, carcass traits, and meat quality in Simmental beef cattle.Methods: Thirty Simmental bulls with an initial body weighing 578.4±14.7 kg were randomly assigned to three dietary treatments for 90 d, with 10 animals per treatment. All animals received the same basal total mixed ration, to which the treatment supplements were added. The treatments were CON, unprotected glucose (150 g/d) plus coating fat (150 g/d); T1, RPG (100 g/d) plus unprotected glucose (100 g/d) and coating fat (100 g/d); and T2, RPG (300 g/d). Growth performance was recorded throughout the trial. At the end of the experiment, colonic digesta were collected for fermentation and bacterial community analyses, and carcass traits and meat quality were evaluated after slaughter.Results: T1 and T2 exhibited higher average daily gains (ADGs) compared to CON (p<0.05), while feed efficiency differed marginally among treatments (p = 0.049). In colonic digesta, propionate concentrations were higher in T1 and T2 than in CON, and butyrate concentration was higher in T2 than in CON and T1 (p<0.05). Alpha diversity was not affected by treatment; however, unweighted UniFrac-based principal coordinate analysis showed differences in the overall colonic bacterial community structure among treatments. At the phylum and genus levels, several taxa showed nominal differences based on raw p values, but these were not retained after false discovery rate correction. Hot carcass weight and meat weight were greater in T1 and T2 than in CON (p<0.05). Intramuscular fat content was higher in T2 than in CON (p<0.05), whereas most other meat quality traits were not significantly affected.Conclusion: Under the conditions of this study, the supplementation strategies containing RPG were associated with increased overall ADG, hot carcass weight, and meat weight in Simmental beef cattle. These strategies were also associated with higher colonic propionate and butyrate levels, indicating changes in hindgut fermentation. The higher-RPG strategy (T2) was associated with increased intramuscular fat content.

Ensiling grass with microbial inoculants is a promising strategy to enhance forage quality, animal performance, and environmental sustainability. This study evaluated the effects of a multi-strain inoculant (Lactobacillus plantarum, L. buchneri, Propionibacterium acidipropionici, and P. thoeni) on silage fermentation, nutrient digestibility, milk production, methane emissions, and rumen microbiota in dairy cows. In a 2 × 2 crossover design, 24 lactating Polish Holstein–Friesians were fed total mixed rations differing only in grass silage treated with or without inoculant. Inoculated silage had lower pH (4.56 vs. 5.06; p = 0.02) and higher crude protein (129 vs. 111 g/kgDM; p < 0.05). Cows fed inoculated silage showed higher ruminal propionate (28.3 vs. 26.3 mM; p = 0.03), reduced ammonia (7.61 vs. 8.67 mM; p = 0.02), and fewer protozoa (1.21 vs. 1.66 × 10⁵/mL; p = 0.03). Nutrient digestibility improved (p < 0.05), while methane emissions declined both per cow (368 vs. 397 g/d; p = 0.01) and per kgDMI (15.1 vs. 16.5; p = 0.01). Milk yield increased (p = 0.04), and the fatty acid profile improved. Our study revealed that cows fed inoculated silage had higher nutrient digestibility, lower methane emissions, and microbial shifts in the rumen detected by 16S rRNA sequencing (p < 0.05).

This study aimed to explore the mechanism by which increasing the temperature of drinking water in winter promotes sheep growth from a microbial perspective. A total of 12 healthy male Hu sheep were evenly divided into two groups: one with drinking water at 12°C (WT12) and the other at 25°C (WT25), and they were raised for 60 days in the cold winter. The WT25 group exhibited higher average daily gain, serum immunoglobulin G, total antioxidant capacity, glutathione peroxidase, and superoxide dismutase, along with lower feed-to-gain ratio, serum cortisol, malondialdehyde, reactive oxygen species, and oxidative stress index when compared to the WT12 group (p<0.05). The concentrations of microbial crude protein, microbial density, autoinducer-2 (AI-2) signaling molecule concentration, and biofilm formation were higher in the WT25 group, while the ammonia nitrogen concentration was lower (p<0.05). The relative abundances of Muribaculum and Clostridia UCG-014, as well as the predicted metabolic pathways related to lipid metabolism, were lower in the WT25 group, whereas the metabolism of other amino acids showed increased abundances (p0.05). Metabolomics analysis identified 12 differential metabolites, four of which were correlated with Muribaculum, Raoultibacter, and Coriobacteriales Incertae Sedis. These results indicate that heated drinking water in winter could improve growth performance by increasing rumen bacterial biofilm formation and enhancing serum antioxidant capacity in Hu sheep. This study establishes correlations between rumen microbial quorum sensing and key factors such as animal growth phenotypes, rumen metabolic characteristics, and specific bacterial genera. It offers innovative perspectives on enhancing animal feed efficiency through the modulation of rumen bacterial quorum sensing.

Objective: The objective of this study was to evaluate the growth performance, rumen fermentation parameters and bacterial community of post-weaning dairy calves in response to five diets varying in corn silage (CS) inclusion.Methods: A total of forty Holstein weaned bull calves (80±3 days of age;128.2±5.03 kg at study initiation) were randomized into five groups (8 calves/group) with each receiving one of five dietary treatments offered as total mixed ration in a 123-d feeding study. Dietary treatments were control diet (CON; 0% CS dry matter [DM]); Treatment 1 (T1; 27.2% CS DM); Treatment 2 (T2; 46.5% CS DM); Treatment 3 (T3; 54.8% CS DM); and Treatment 4 (T4; 67.2% CS DM) with all diets balanced for similar protein and energy concentration.Results: Results showed that calves offered CS had greater average daily gain, body length and chest depth growth, meanwhile altered rumen fermentation indicated by decreased rumen acetate concentrations. Principal coordinate analysis showed the rumen bacterial community structure was affected by varying CS inclusion diets. Bacteroidetes and Firmicutes were the predominant bacterial phyla in the calf rumens across all treatments. At the genus level, the abundance of Bacteroidales_RF16_group was increased, whereas Unclassified_ Lachnospiraceae was decreased for calves fed CS. Furthermore, Spearman’s correlation test between the rumen bacteria and rumen fermentation parameters indicated that Bacteroidales_RF16_group and Unclassified Lachnospiraceae were positively correlated with propionate and acetate, respectively.Conclusion: The results of the current study suggested that diet CS inclusion was beneficial for post-weaning dairy calf growth, with 27.2% to 46.5% CS of diet DM recommended to achieve improved growth performance. Bacteroidales_RF16_group and Unclassified Lachnospiraceae play an important role in the rumen fermentation pattern for post-weaning calves fed CS.

The present experiment was carried out to analyze the longitudinal changes in milk microorganisms. For this purpose, milk samples were collected from 12 healthy cows (n = 96; six primiparous cows and six multiparous cows) at eight different time points. The characteristics and variations in microbial composition were analyzed by 16S rRNA gene high-throughput sequencing. In the primiparous group, higher and more stable alpha diversity was observed in transitional and mature milk compared with the colostrum, with no significant difference in alpha diversity at each time point in the multiparous group. Proteobacteria, Firmicutes, Bacteroidota, and Actinobacteriota were the most dominant phyla, and Pseudomonas, UCG-005, Acinetobacter, Vibrio, Lactobacillus, Bacteroides, Serratia, Staphylococcus, and Glutamicibacter were the most dominant genera in both primiparous and multiparous cow milk. Some typically gut-associated microbes, such as Bacteroides, UCG-005, and Rikenellaceae_RC9_gut_group, etc., were enriched in the two groups. Biomarker taxa with the day in time (DIM) were identified by a random forest algorithm, with Staphylococcus showing the highest degree of interpretation, and the difference in milk microbiota between the two groups was mainly reflected in 0 d–15 d. Additionally, network analysis suggested that there were bacteria associated with the total protein content in milk. Collectively, our results disclosed the longitudinal changes in the milk microbiota of primiparous and multiparous cows, providing further evidence in dairy microbiology.

This study was carried out to evaluate the nutrient intakes and growth of dairy heifers offered an alfalfa silage-corn silage diet (CON; 14.3% crude protein, 61.1% total digestible nutrients, 47.9% neutral detergent fiber) compared with diets containing 1 of 2 types of sorghum-sudangrass (SS) silages: conventional or photoperiod sensitive. The objective of the study was to determine the potential to use SS to control dry matter (DM) and nutrient intakes and weight gain. Both diets were similar in nutrient composition, with approximately 13% crude protein, 60 to 61% total digestible nutrients, and 55% neutral detergent fiber. Seventy-two Holstein heifers (16-18 mo at study initiation) were blocked by initial body weight (light = 422 ± 12.8 kg; medium = 455 ± 14.8 kg; heavy = 489 ± 16.7 kg) with 3 pens assigned to each weight block (8 heifers/pen; 24 heifers/block). The 3 diets were randomly allocated to the pens within each block and offered for 12 wk. Heifers offered the CON diet had greater DM, protein, and energy intakes compared with those offered the SS silage-based diets due to the greater neutral detergent fiber concentration of the SS diets. With lower DM and nutrient intakes, average daily gain was in the recommended range (0.8-1 kg/d for Holstein heifers) for heifers offered the SS silage-based diets (mean of 0.92 kg/d for both SS diets vs. 1.11 kg/d for CON). Sorting behaviors for heifers offered both SS diets were more aggressive against long, medium, and short particles compared with those of heifers offered the CON diet; however, heifers sorted large particles from photoperiod-sensitive silage more aggressively than those from conventional silage. Based on this study, SS silage-based diets can control the DM and energy intakes for heifers and maintain optimum growth rates, with harvesting at a shorter chop length likely helping to alleviate sorting issues.

The present experiment was carried out to assess the effects of reconstituted milk (RM), acidified reconstituted milk (ARM), and acidified fresh milk (AFM) on growth performance, diarrhea rate, and hematological parameters of preweaning dairy calves. For this purpose, a total of 27 Holstein female calves (one month of age) with initial body weight of (67.46 ± 4.08) kg were divided into three groups in such a way that each group contained nine calves. Calves were housed individually, and starter was offered ad libitum to each calf. The dietary treatments were RM, ARM, and AFM. The highest milk intake was observed in calves receiving AFM as compared to other treatments (p < 0.01). Calves fed AFM had more feed intake than those fed ARM and RM (p < 0.01). Feed efficiency was significantly lower for calves offered ARM than those offered RM and AFM (p < 0.01). A lower withers height growth was found for calves fed RM than those fed ARM and AFM (p p < 0.05). These findings suggested that ARM and AFM had positive effects on growth performance and health status of the preweaning dairy calves.

The experiment evaluated the effect of nutrition levels and sex on the growth performance, carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.