Search Results (522)

Leaves, the main by-product of lingonberry harvesting, can be effectively used as a functional feed additive due to their health-promoting properties. This study evaluated the effects of lingonberry leaf (LL) supplementation on rumen fermentation, protozoal populations, and gastrointestinal morphology in sheep. Eight one-year-old Polish Mountain Sheep ewes (mean body weight: 33 kg) were allocated to a control (basal diet; forage-to-concentrate ratio 60:40) or an experimental group (basal diet + 9.30 g/kg DM dried LLs) in a completely randomised design (n = 4 per group) over 34 days. Both diets were formulated to be isoenergetic and isonitrogenous. LL additive significantly reduced Isotrichidae protozoal counts (p < 0.001) and ruminal pectinolytic activity (p = 0.043), without altering short-chain fatty acid (SCFA) or methane concentrations (p > 0.1). Histological analyses showed increased ruminal papilla width and surface area (p < 0.001) and decreased duodenal villus height and muscular layer thickness (p < 0.01). Inflammatory lesions (reddish foci) were identified in the liver in both groups. These findings demonstrate that LL supplementation affected specific protozoal population, fibrolytic activity, and gastrointestinal morphology. Further study on a larger number of animals is recommended to validate the effects and assess the safety and efficacy of LLs as a dietary additive in ruminant nutrition. Full article

Glycerol fatty acid esters (GFAEs) are recognized for their potential to improve lipid metabolism, energy utilization, and gut health due to their excellent emulsifying and antimicrobial properties. The objective of this research was to investigate the effects of dietary GFAE supplementation on production performance, serum biochemical profiles, and rumen fermentation in beef cattle. Thirty crossbred Simmental bulls, averaging 507.42 ± 9.59 kg in body weight, were assigned to three distinct cohorts, with 10 animals in each cohort. The CON cohort was fed a basal diet devoid of GFAE, whereas the treatment cohorts (GFAE1 and GFAE2) received GFAE supplements at concentrations of 0.1% and 0.2% of the dietary dry matter, respectively. Compared with the control group, supplementation with 0.1% GFAE significantly increased the ADG of beef cattle by 12.14% (p < 0.05); compared with the GFAE2 group, ADG was 7.86% higher (p > 0.05). The digestibility of NDF and ADF was significantly enhanced in the GFAE1 group relative to the control group (p < 0.05). Dietary GFAE supplementation significantly elevated rumen acetate, propionate, and total volatile fatty acid concentrations in both the GFAE1 and GFAE2 groups compared to the control group (p < 0.05). In contrast to the control group, there was a notable rise in serum levels of T-AOC, UREA, and TG in both GFAE1 and GFAE2 groups (p < 0.05). Conversely, the concentration of HDL-C was significantly decreased in the GFAE2 group. Additionally, at the phylum level, the abundance of Fibrobacterota was significantly higher in the GFAE1 group than in the control group (p < 0.01). At the genus level, the proportions of Bacteroides and Fibrobacter were significantly higher in the GFAE1 group compared to the control group (p < 0.05). In conclusion, this study demonstrates that the addition of 0.1% GFAE to beef cattle diets significantly enhances the digestibility of ADF and NDF nutrients, increases serum total antioxidant capacity, urea, and triglycerides, optimizes rumen fermentation parameters and microbial community structure, and ultimately improves production performance. As a result of the findings from this research, it is suggested that 0.1% GFAE be incorporated into the diet for beef cattle. Full article

The aim of this study was to determine, through meta-analysis, the effects of malic acid/malate addition on ruminal and blood parameters and diet digestibility in cattle. The literature search was conducted in Web of Science, Science Direct, and Google Scholar using the terms “organic acids”, “malic acid”, “malate”, and “bovine”. The database was composed of papers published between 1980 and 2023. The average effect of malate/malic acid inclusion was calculated using the “DerSimonian and Laird” random effects model. Meta-regression and subgroup analyses were conducted to explore sources of heterogeneity. Overall, malic acid (MAC) addition did not significantly affect rumen pH (ES = 0.310, p = 0.17), but subgroup analysis showed that malate increased pH (ES = 1.420, p < 0.01). MAC increased rumen propionate (ES = 0.560, p < 0.01) and total volatile fatty acids (VFAs; ES = 0.508, p = 0.03), while reducing the acetate-to-propionate ratio (p < 0.01). Starch and NDF intake were significant covariates affecting pH and VFA-related variables. MAC improved total-tract digestibility of dry matter (DM; ES = 0.547, p ≤ 0.05), crude protein (CP; ES = 0.422, p ≤ 0.05), and acid detergent fiber (ADF; ES = 0.635, p ≤ 0.05). It increased glucose levels (Overall ES = 0.170, p = 0.05) and reduced NEFA (Overall ES = −0.404, p = 0.03). In conclusion, the effectiveness of MAC depends on its chemical form. Improvements in rumen pH, fiber degradation, and blood parameters suggest more efficient energy use and potential metabolic benefits. The influence of diet-related covariates suggests that the response to MAC may vary depending on the nutritional composition of the diet. Full article

Optimizing the metabolizable protein level in ruminant diets represents a promising strategy to increase nitrogen use efficiency and mitigate environmental pollution. This study explored the impacts of varying metabolizable protein (MP) levels on amino acid (AA) balance, nitrogen (N) utilization, and the ruminal microbiota in Hu lambs. Fifty-four female Hu lambs of 60 d old, with an average body weight (BW) of 18.7 ± 2.37 kg, were randomly allocated to three dietary MP groups: (1) low MP (LMP, 7.38% of DM), (2) moderate MP (MMP, 8.66% of DM), and (3) high MP (HMP, 9.93% of DM). Three lambs with similar BW within each group were housed together in a single pen, serving as one experimental replicate (n = 6). The feeding trial lasted for 60 days with 10 days for adaptation. The final BW of lambs in the MMP and HMP groups increased (p < 0.05) by 5.64% and 5.26%, respectively, compared to the LMP group. Additionally, lambs fed the MMP diet exhibited an 11.6% higher (p < 0.05) average daily gain than those in the LMP group. Increasing dietary MP levels enhanced (p < 0.05) N intake, urinary N, retained N, and percent N retained, but decreased apparent N digestibility (p < 0.05). Urinary uric acid, total purine derivatives, intestinally absorbable dietary protein, microbial crude protein, intestinally absorbable microbial crude protein, and actual MP supply all increased (p < 0.05) with higher MP values in the diet. The plasma concentrations of arginine, lysine, methionine, phenylalanine, threonine, aspartic acid, proline, total essential AAs, and total nonessential AAs were the lowest (p < 0.05) in the LMP group. In the rumen, elevated MP levels led to a significant increase (p < 0.05) in the ammonia N content. The relative abundances of Candidatus_Saccharimonas, Ruminococcus, and Oscillospira were the lowest (p < 0.05), whereas the relative abundances of Terrisporobacter and the Christensenellaceae_R-7_group were the highest (p < 0.05) in the MMP group. In conclusion, the moderate dietary metabolizable protein level could enhance growth performance, balance the plasma amino acid profiles, and increase nitrogen utilization efficiency in Hu lambs, while also altering the rumen bacterial community by increasing beneficial probiotics like the Christensenellaceae_R-7_group. Full article

The purpose of this study was to explore the effects of co-ensiling Caragana korshinskii with different proportions of oat grass on silage fermentation quality, chemical composition, in situ rumen degradability and in vitro rumen fermentation characteristics. C. korshinskii and oat grass were mixed at different ratios of 100:00, 90:1, 80:2, 70:30, 60:40 and 50:50. Each ratio of mixture was ensiled for 7, 14, 30, 45 and 60 days at room temperature (25 °C), with 30 bags per ratio, for a total of 180 bags. We further investigated the dynamic profiles of the bacterial community during ensiling and in vitro rumen fermentation. The results showed that co-ensiling C. korshinskii and oat grass decreased the pH values and increased the content of lactic acid and acetic acid compared with ensiling C. korshinskii alone. C. korshinskii ensiled with oat grass at a ratio of 70:30 (70% C. korshinskii) showed the best fermentation quality, which was related to higher relative abundance of Lactobacillus and Weissella. The silage with the ratio of 70:30 (70% C. korshinskii) showed higher dry matter digestibility and the more production of gas and total volatile fatty acids, compared with fresh C. korshinskii. In conclusion, C. korshinskii co-ensiled with oat grass at a ratio of 70:30 could enhance the fermentation quality and digestibility of C. korshinskii. Full article

This study aimed to evaluate the effect of including silage from devilfish waste (SF-Hypostomus plecostomus) and probiotics (PB-Pediococcus acidilactici BX-B122 and Bacillus coagulans BX-B118) in ruminants on greenhouse gas production. The diets evaluated contained 0, 8, 14 and 20% of silage made from SF and the addition of PB at a dose of 0.2 mL/g of diet, using steers and sheep (rams) as rumen inoculum donors in a completely randomized statistical design with a 2 × 4 × 2 factorial arrangement. Asymptotic gas production (GP) was influenced (p < 0.01) by the interactions between rumen liquor (RL), SF, and PB. The inclusion of SF and PB resulted in a higher (p < 0.01) GP rate in sheep; however, the values were reduced with increasing levels of SF. Asymptotic CH₄ in the rumen fluid of steers decreased with an increasing SF percentage up to 14%. Probiotics had different effects on the rumen fluid of sheep and steers. In steers, probiotics substantially reduced (p < 0.01) CH₄ synthesis while supplementation increased it in sheep rumen fluid. Similarly, diets with probiotics had higher CO formation (p < 0.05) in sheep and steer liquor. Similarly, CO decreased (p < 0.05) with increasing levels of SF. In the rumen fluid of sheep and steers, the probiotics were found to reduce H₂S, while there was an SF-dose-dependent decrease in H₂S concentration. The ruminal pH and dry matter digestibility of sheep were higher than in steers. It can be concluded that increasing SF levels generally reduced the total gas and CH₄ production, with probiotics further enhancing this reduction, especially in CH₄ per unit of gas. Full article

Our previous study has shown that supplementation of 0.50% benzoic acid (BA) increased growth performance, promoted rumen fermentation, and improved the composition and function of rumen microbiota. This research was designed to conduct a deeper exploration of the impacts of dietary supplementation with BA on the apparent digestibility of nutrients and the composition of rectal microbiota in weaned Holstein dairy calves. Sixteen Holstein heifer calves with similar body weights (91.2 ± 0.7 kg) were selected and randomly allocated into two groups, each comprising eight calves. Calves in the control group (CON group) were fed with a basal diet, while those in the benzoic acid group (BA group) were fed with the basal diet supplemented with 0.50% benzoic acid (on a dry matter basis). The experimental period started at 60 days of age and ended at 102 days of age, lasting for a total of 42 days. The calves were weaned at 60 days of age, with a transition period of 7 days. Feed samples were collected every two weeks, fecal samples were collected from 99 to 101 days of age, and blood samples were collected at 102 days of age. The results showed that supplementation with BA did not influence the digestibility of dry matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, calcium, and phosphorus between the two groups. Compared with the CON group, BA supplementation tended to decrease the total cholesterol (TC) in the serum of the calves (p = 0.067). Supplementation with BA increased the relative abundances of the two beneficial bacteria, Bifidobacterium and Bifidobacterium pseudolongum (p < 0.05, LDA > 2), but decreased that of the harmful bacterium, Clostridium sensu stricto 1, in the rectum of dairy calves. The microbial functional prediction revealed that the fecal microbial metabolism involved in primary bile acid biosynthesis was higher in the calves from the BA group. In conclusion, the present study demonstrated that adding 0.50% BA to the diet did not influence the apparent nutrient digestibility, but improved rectal microbiota health, which finally promoted the growth performance in weaned Holstein dairy calves. Full article

The rumen and intestinal microbiota play a pivotal role in the digestion and absorption processes of ruminants. Elucidating the mechanisms by which gastrointestinal microbiota influence the feed conversion ratio (FCR) in ruminants is significantly important for enhancing feed utilization efficiency in these animals. In this study, RT-qPCR, 16S rRNA sequencing, and metabolomic techniques were systematically employed to compare the microbial community structures in the rumen, cecum, and rectum, as well as the differences in rumen metabolites between high- and low-FCR Tan sheep. The results showed that, compared to the HFCR group of Tan sheep, the LFCR group exhibited a significant reduction in unclassified_f__Selenomonadaceae, Blvii28_wastewater-sludge_group, and Papillibacter in the rumen; a significant increase in Lachnospiraceae_AC2044_group and Sanguibacteroides; a significant reduction in unclassified_f__Peptostreptococcaceae, Clostridium_sensu_stricto_1, and Parasutterella in the cecum; a significant increase in norank_f__Bacteroidales_UCG-001; and a significant reduction in norank_f__Muribaculaceae, Blautia, and Turicibacter in the rectum. There is a significant positive correlation between Parasutterella in the cecum and three microorganisms, including unclassified_f__Selenomonadaceae, in the rumen. Additionally, Blvii28_wastewater-sludge_group was positively correlated with Lactobacillus. Furthermore, unclassified_f__Selenomonadaceae in the rumen was positively correlated with Turicibacter, unclassified_f__Peptostreptococcaceae, and Breznakia in the rectum. Blvii28_wastewater-sludge_group also showed positive correlations with Blautia, norank_f__Muribaculaceae, and Clostridium_sensu_stricto_1, while Papillibacter was positively correlated with Faecalitalea. The metabolomic results indicated that, compared to the HFCR group, 261 differential metabolites, including Phenylacetylglutamine and Populin, in the rumen of Tan sheep in the LFCR group were significantly downregulated, whereas 36 differential metabolites, including Glycyl-L-tyrosine, were significantly upregulated. Furthermore, the rumen microbe unclassified_f__Selenomonadaceae exhibited positive correlations with significantly differential metabolites such as L-tryptophan, Etiocholanolone glucuronide, N-acetyl-O-demethylpuromycin, and 6-deoxyerythronolide B. Blvii28_wastewater-sludge_group and Papillibacter also exhibited positive correlations with Icilin. High and low FCRs in the rumen of Tan sheep were investigated, especially in relation to unclassified_f__Selenomonadaceae, Blvii28_wastewater-sludge_group, and Papillibacter. Correlations can be seen with microorganisms such as Parasutatella and Lactobacillus in the cecum; Turicibacter, norank_f__Bacteroideales_UCG-001, and Blautia in the rectum; and metabolites such as L-tryptophan, Etiocholanolone glucuronide, and N-acetyl-O-demethylpuromycin. This reveals the role of microorganisms in the digestion and absorption of Tan sheep feed, thus providing a preliminary basis for further research on the microbial regulation of ruminant animal feed utilization and a theoretical basis for improving Tan sheep feed utilization efficiency. Full article

Utilizing straw feed is an effective strategy to optimize straw resource utilization by incorporating microbial degradation agents to expedite lignocellulose breakdown and enhance feed efficiency. Lignocellulose-degrading species and microbial communities are present in various Earth ecosystems, including the rumen of ruminants, insect digestive tracts, forest soil, and microbial populations in papermaking processes. The rumen of ruminants harbors a diverse range of microbial species, making it a promising source of lignocellulose-degrading microorganisms. Exploring alternative systems like insect intestines and forest soil is essential for future research. Current studies primarily rely on traditional microbial isolation techniques to identify lignocellulose-degrading strains, underscoring the necessity to transition to utilizing microbial culturomics and genome-editing technologies for discovering and manipulating cellulose-degrading microbes. This review provides an overview of lignocellulose-degrading microbial communities from diverse environments, encompassing bacterial and fungal populations. It also delves into the use of metagenomic, metatranscriptomic, and metaproteomic approaches to pinpoint highly efficient cellulase genes, along with the application of genome-editing tools for engineering lignocellulose-degrading microorganisms. The primary objective of this review is to offer insights for further exploration of potential lignocellulose-degrading microbial resources and high-performance cellulase genes to enhance roughage utilization in ruminant rumen ecosystems. Full article

This study evaluated the effects of feedstuffs and additives in dairy cow rations on rumen methane production and nitrate content in groundwater. Two basal rations and their supplements were analyzed in regard to proximate parameters, and an in vitro rumen fermentation system assessed methane release and nitrate levels over 72 h. Supplementing dairy cow rations with Brassica rapa (BR) boosted the ether extract content, while silage produced the highest amount of methane. Rapidly degrading substrates like BR and ground maize produced methane faster, but in smaller amounts, than straw and silage. BR, Opuntia ficus-indica (OFI), and Posidonia oceanica (PO)-supplemented rations had mixed effects; PO reduced the methane yield, while OFI increased methane production rates. BR-supplemented rations had the lowest nitrate levels, making it suitable for anaerobic digestion. The multivariate analysis showed strong correlations between crude protein, dry matter, and ash, while high-nitrate substrates inhibited methane production, supporting the literature on the role of nitrates in reducing methanogenesis. These results emphasize the need to balance nutrient composition and methane mitigation strategies in dairy cow ration formulations. Full article

The growing demand for biofuels, especially ethanol produced from corn, has driven the production of co-products such as dried distillers grains with solubles (DDGS). With a high protein content (around 30%), fiber, and minerals, DDGS presents an economical alternative for animal nutrition, replacing traditional sources like soybean meal while maintaining productive performance and reducing costs. This study evaluated the total replacement of soybean meal with DDGS in the diet of confined Holstein cattle, focusing on weight gain, feed intake, digestibility, feed efficiency, animal health, meat quality, and economic viability. The 24 animals received diets with 80% concentrate, containing either DDGS or soybean meal, and no significant differences were observed in terms of body weight (p = 0.92), feed intake (p = 0.98), or feed efficiency (p = 0.97) between the two treatments. The average daily gain was 1.25 and 1.28 kg for cattle in the DDGS and soybean meal groups, respectively (p = 0.92). Regarding metabolic and digestive parameters, no relevant changes were found in blood levels, except for higher serum cholesterol (p = 0.03) levels in animals fed DDGS. The digestibility of neutral detergent fiber (NDF) (p = 0.03) and acid detergent fiber (ADF) (p = 0.05) was lower in the DDGS group, while the digestibility of ether extract was higher (p = 0.02). Rumen fluid analysis revealed an increase in the production of short-chain fatty acids (p = 0.01), such as acetic and butyric acids (p = 0.01), in the DDG-fed animals. In terms of meat quality, animals fed DDGS produced meat with lower levels of saturated fatty acids (SFA) (p = 0.05) and higher levels of unsaturated fatty acids (UFA) (p = 0.02), especially oleic acid (p = 0.05). This resulted in a healthier lipid profile, with a higher UFA/SFA ratio (p = 0.01). In terms of economic viability, DDGS-based diets were 10.5% cheaper, reducing the cost of production per animal by 7.67%. Profitability increased by 110% with DDGS compared to soybean meal, despite the high transportation costs. Therefore, replacing soybean meal with DDGS is an efficient and economical alternative for feeding confined cattle, maintaining zootechnical performance, increasing meat lipid content and improving fatty acid profile, and promoting higher profitability. This alternative is particularly advantageous in regions with easy access to the product. Full article

In vitro methods have advanced research on rumen microbiology and fermentation. However, artificial saliva formulation may need adjustments, particularly in urea content, for modern diets, warranting further research. This study investigated the effects of different nitrogen (N) levels in artificial saliva on ruminal fermentation and digestion in diets for dairy cows using a Rusitec^® system. Eighteen fermenters tested three saliva treatments with different N levels: a standard saliva as the control and two treatments with N reduced by 15% and 30%. Data were analyzed as a completely randomized design using the MIXED procedure of SAS (v. 9.4), with linear and quadratic contrasts tested for treatment effects (significance set at p ≤ 0.05). Results showed that altering N content had no significant effect on pH, ammonia concentrations, or NH₃-N outflow, nutrient digestibility (dry matter, crude protein, fiber, and starch), gas and methane production, or volatile fatty acid concentrations. The efficiency of microbial protein synthesis and N flow exhibited quadratic responses, with the lowest values observed at the highest level of N reduction in the saliva (−30%). These findings suggest that although ruminal function and digestion remain stable with reduced N, microbial protein synthesis efficiency may decline beyond a threshold. Full article

The objective of this study was to evaluate whether the addition of fibrolytic enzymes to the diet of cattle in confinement improves feed digestibility weight gain; as well as evaluating the profile of fatty acids in the ruminal environment and in meat fatty acids profile. In total, 24 male dairy cattle (Holstein) aged 8 months and weighing an average of 212 kg, were divided into 2 groups: control (without additive) and treatment (0.25 g of enzymes/kg of dry matter of total diet). The experiment lasted 120 days. The first 20 days are allocated for the adaptation period. During the study, samples of blood, ruminal fluid, and feces were collected, as well as weighing the cattle and measuring their daily feed consumption. There was no effect of treatment on body weight, feed intake, feed efficiency, and nutrient digestibility (p > 0.05). Cholesterol levels were higher in the serum of cattle that consumed the enzyme; serum amylase activity was higher in cattle that received the additive only on day 120 of the experiment (p < 0.05). There was a greater amount of volatile fatty acids in the ruminal fluid, combined with a greater amount of acetic acid. The amount of fat in the meat of cattle that consumed fibrolytic enzymes was higher compared to the control group (p < 0.05). Meat from cattle in the treatment group had lower amounts of saturated fatty acids and higher amounts of unsaturated fatty acids (p < 0.05). The fibrolytic enzymes addition altered rumen fermentation in such a way that lipid metabolism was changed, which had a serious impact on cholesterol and tissue levels, that is, in the meat that had a greater amount of total lipids, an unsaturated fat. Full article

The rumen is a critical organ that facilitates nutrient digestion in ruminant animals. However, the biological mechanisms by which rumen microbiota and its metabolites enable Lactobacillus to modulate rumen structure and maintain functional homeostasis under fattening feeding conditions remain poorly understood. In this study, 80 male Pamir yaks were selected, and a 170-day data collection phase was implemented. Correlation phenotypic data and multi-omics analyses (rumen microbial sequencing and rumen epithelial metabolomics) were conducted to investigate the regulatory effects of Lactobacillus supplementation on rumen microbiota and metabolic processes in a concentrate-based rearing yak model. The results demonstrated that feeding a high-energy diet may impair yak ruminal histomorphology, microbiota composition, and function while negatively modulating rumen microbiota–metabolic profiles associated with specific ruminal microbial communities and functions. Lactobacillus intervention treatment optimized the yak ruminal microbiome composition (mucous layer maturation was promoted, Prevotella and Ruminococcus abundance were reduced, and Fibrobacter and Muribaculaceae abundance were increased), thereby altering metabolite concentrations involved in various metabolic pathways under a high-energy feeding pattern (fatty acid metabolism pathways were upregulated). These alterations elucidated the beneficial impacts of the Lactobacillus supplementation strategy on yak ruminal health without compromising the high-energy intensive rearing pattern. Furthermore, the regulated ruminal microbiome metabolites may serve as potential biomarkers for future investigations into the functional impacts of Lactobacillus intervention treatment on healthy feeding strategies for yaks. Full article