Rumen Fermentation Parameters Research Articles

Effects of Replacing Soybean Meal with Cottonseed Meal, Peanut Meal, Rapeseed Meal, or Distillers’ Dried Grains with Solubles on the Growth Performance, Nutrient Digestibility, Serum Parameters, and Rumen Fermentation in Growing Lambs

Considering the frequently large price fluctuations for soybean meal, an alternative is the increased use of locally produced high-protein ingredients. The objective of this study was to evaluate the effects of the total replacement of soybean meal with different sources of protein on the growth performance, nutrient digestibility, serum parameters, rumen fermentation parameters, and bacterial communities in growing lambs. Sixty sheep with similar body weights (38.46 ± 0.71 kg) were distributed to one of five treatments: soybean meal (SBM); cottonseed meal (COM); peanut meal (PEM); rapeseed meal (RAM); and distillers’ dried grains with solubles (DDGS). The experiment lasted 62 days with a 10-day adaptation period and a 52-day growing period. The results indicated that the body weight and average daily gain were not affected by different protein sources (p > 0.05), but the dry matter intake of the SBM group was lower than that of the other groups (p < 0.05); otherwise, the feed efficiency was higher (p < 0.05). The digestion of dry matter was higher in the SBM, COM, and RAM groups than in the DDGS and PEM groups (p < 0.05). Meanwhile, compared to the other groups, the SBM group had the highest digestion of gross energy and crude protein (p < 0.05). In addition, the concentration of glutathione peroxidase was highest in the SBM group (p < 0.05). Regarding the rumen fermentation, the SBM group had the highest concentration of NH3-N (p < 0.05). The rumen bacterial community was not affected by treatments (p > 0.05). In conclusion, the total replacement of soybean meal with cottonseed, peanut, rapeseed, or DDGS reduced digestibility but did not impact the body weight or average daily gain of growing lambs and had no effect on the immune function and rumen bacterial community; thus, they can be used to substitute the soybean meal.

Mechanistic insights into rumen function promotion through yeast culture (Saccharomyces cerevisiae) metabolites using in vitro and in vivo models

IntroductionYeast culture (YC) enhances ruminant performance, but its functional mechanism remains unclear because of the complex composition of YC and the uncertain substances affecting rumen fermentation. The objective of this study was to determine the composition of effective metabolites in YC by exploring its effects on rumen fermentation in vitro, growth and slaughter performance, serum index, rumen fermentation parameters, rumen microorganisms, and metabolites in lambs.MethodsIn Trial 1, various YCs were successfully produced, providing raw materials for identifying effective metabolites. The experiment was divided into 5 treatment groups with 5 replicates in each group: the control group (basal diet without additives) and YC groups were supplemented with 0.625‰ of four different yeast cultures, respectively (groups A, B, C, and D). Rumen fermentation parameters were determined at 3, 6, 12, and 24 h in vitro. A univariate regression model multiple factor associative effects index (MFAEI; y) was established to correlate the most influential factors on in vitro rumen fermentation with YC metabolites (x). This identified the metabolites promoting rumen fermentation and optimal YC substance levels. In Trial 2, metabolites in YC not positively correlated with MFAEI were excluded, and effective substances were combined with pure chemicals (M group). This experiment validated the effectiveness of YC metabolites in lamb production based on their impact on growth, slaughter performance, serum indices, rumen parameters, microorganisms, and metabolites. Thirty cross-generation rams (Small tail Han-yang ♀ × Australian white sheep ♂) with good body condition and similar body weight were divided into three treatment groups with 10 replicates in each group: control group, YC group, pure chemicals combination group (M group).ResultsGrowth performance and serum index were measured on days 30 and 60, and slaughter performance, rumen fermentation parameters, microorganisms, and metabolites were measured on day 60. The M group significantly increased the dressing percentage, and significantly decreased the GR values of lambs (p < 0.05). The concentration of growth hormone (GH), Cortisol, insulin (INS), and rumen VFA in the M group significantly increased (p < 0.05).DiscussionThese experiments confirmed that YC or its screened effective metabolites positively impact lamb slaughter performance, rumen fermentation, and microbial metabolism.

Dataset of the rumen microbiota and epithelial transcriptomics and proteomics in goat affected by solid diets

Although early solid diet supplementation is a common practice to improve the growth and development in goat kids, its biological mechanism how solid diet induces rumen microbiota and epithelial development is still unknow. In this study, rumen fermentation parameters, 16S rRNA sequencing for rumen content and epithelial microbiota, transcriptomics and proteomics of epithelium were determined to classify the effects of solid diet supplementation. Here, we classified the changes of goat phenotypes (i.e., growth performance, rumen fermentation and development) and linked them to the changes of rumen microbiota, transcriptome and expressed proteins. The mechanism of solid diet improving rumen development was elucidated preliminarily. Moreover, different roles between the rumen content and epithelial microbiota were identified. Thess datasets expands our understanding of the association between the early diet intervention and rumen development, providing the useful information how nutrient strategy affects rumen function and subsequently improves the host growth. The generated data provides insights in the importance of rumen niche microbiota and microbe-host interactions, which benefits future studies.

Effects of Steviol Glycosides on Growth Performance, Ruminal Fermentation and Microbial Diversity of Hu Sheep.

The experiment was conducted to investigate the potential effects of steviol glycosides on growth performance, rumen fermentation processes, and microbial diversity in Hu sheep. A single-factor design was used for the trial. Twenty healthy weaned Hu lambs, possessing comparable body weights averaging 18.31 ± 1.24 kg, were randomly allocated into two distinct groups: the control group (CON) and the experimental group (STE), with each comprising 10 lambs. The CON was fed the basal diet, and the STE was supplemented with 0.07% steviol glycosides based on the basal diet. During the experimental period, variations in body weight and feed intake were closely monitored and recorded. After feeding for 90 d, blood was collected to determine blood biochemical indices, and rumen fluid samples were gathered for an in-depth analysis of rumen fermentation parameters and microbial diversity. The outcomes revealed no statistically significant differences in growth performance or serum biochemical indices between the two groups (p > 0.05). Rumen pH in STE and CON was within the normal range. The rumen ammonia nitrogen (NH3-N) and acetic acid (AA) content of STE decreased significantly compared with CON (p < 0.05). No significant variations were observed in the levels of other volatile fatty acids (VFAs) between the two groups (p > 0.05). The rumen microbial OTUs count, as well as the Shannon, Simpson, Chao1, and Ace indices, were notably lower in the STE group compared to the CON group (p < 0.05). Additionally, at the phylum level, the relative abundance of Firmicutes, Bacteroidetes, and Proteobacteria collectively accounted for over 97% of the total phylum composition. In comparison to the CON group, the STE group exhibited an increase in the relative abundance of Proteobacteria (p < 0.05), accompanied by a significant reduction in the relative abundance of Patescibacteria and Desulfobacteria (p < 0.05). At the genus level, there was a notable increase in the relative abundance of Prevotella_7 and Succinivibrionaceae_UCG_001 in the STE group, whereas the relative abundance of Rikenellaceae_RC9_gut_group significantly decreased (p < 0.05). According to the correlation analysis between rumen microflora and VFAs, the relative abundance of Succinivibrionaceae_UCG_001 displayed a significant negative correlation with AA (p < 0.05), whereas Lactobacillus exhibited a notable positive correlation with isobutyric acid (IBA) (p < 0.05). In summary, steviol glycosides had no significant effect on the production performance and blood biochemical indexes of Hu sheep. Steviol glycosides can improve rumen fermentation parameters and rumen microflora structure of Hu sheep and have a certain effect on rumen microbial diversity and composition.

Negative energy balance affects perinatal ewe performance, rumen morphology, rumen flora structure, and placental function.

This study investigated the effects of negative energy balance (NEB) on perinatal ewes, with a focus on changes in growth performance, serum biochemical parameters, rumen fermentation, ruminal bacteria composition, placental phenotype-related indicators, and expression levels of genes related to placental function. Twenty ewes at 130 days of gestation were randomly allocated to either the positive energy balance (PEB) or NEB groups. In the experiment, ewes in the PEB group were fed the same amount as their intake during the pre-feeding baseline period, while ewes in the NEB group were restricted to 70% of their individual baseline feed intake. The experiment was conducted until 42 days postpartum, and five double-lamb ewes per group were selected for slaughter. The results demonstrated that NEB led to a significant decrease in body weight, carcass weight, and the birth and weaning weights of lambs (P < 0.05). Additionally, NEB caused alterations in serum biochemical parameters, such as increased non-esterified fatty acids and β-hydroxybutyrate levels and decreased cholesterol and albumin levels (P < 0.05). Rumen fermentation and epithelial parameters were also affected, with a reduction in the concentrations of acetic acid, butyric acid, total acid and a decrease in the length of the rumen papilla (P < 0.05). Moreover, NEB induced changes in the structure and composition of ruminal bacteria, with significant differences in α-diversity indices and rumen microbial community composition (P < 0.05). Gene expression in rumen papilla and ewe placenta was also affected, impacting genes associated with glucose and amino acid transport, proliferation, apoptosis, and angiogenesis (P < 0.05). These findings screened the key microbiota in the rumen of ewes following NEB and highlighted the critical genes associated with rumen function. Furthermore, this study revealed the impact of NEB on placental function in ewes, providing a foundation for investigating how nutrition in ewes influences reproductive performance. This research demonstrates how nutrition regulates reproductive performance by considering the combined perspectives of rumen microbiota and placental function.

Rosa roxburghii tratt residue as an alternative feed for improving growth, blood metabolites, rumen fermentation, and slaughter performance in Hu sheep.

The utilization of agro-industrial by-products, such as fruit residues, presents a promising strategy for providing alternative feed to ruminants amidst rising prices and limited availability of traditional roughage. In this study, we investigated the effects of Rosa roxburghii tratt residue, a local fruit residue in Guizhou province of China, on the growth, blood metabolites, rumen fermentation, and slaughter performance of Hu sheep. Ninety-six sheep were randomly divided into four groups, namely control, treatment 1, treatment 2, and treatment 3, and fed diets containing 0, 10, 20, and 30% Rosa roxburghii Tratt residue, respectively. Feeding varying levels of Rosa roxburghii Tratt residue showed no significant differences in dry matter intake, average daily gain, or the ratio of dry matter intake to average daily gain. However, sheep in the group fed with 30% Rosa roxburghii Tratt residue showed the highest gross profit. Plasma albumin content was lower in groups fed with Rosa roxburghii Tratt residue-containing diets compared to the control group (p < 0.05). Additionally, diet treatment 3 decreased plasma creatinine levels compared to control and treatment 1 (p < 0.05). Sheep in treatment 2 and treatment 3 exhibited higher plasma high-density lipoprotein level than control and treatment 1 (p < 0.05), as well as increased total cholesterol levels compared to control (p < 0.05). There were no significant differences in other plasma metabolites. Rumen pH, N-NH3, volatile fatty acids, and methane levels did not differ significantly among the four groups. However, feeding diets treatment 2 and treatment 3 resulted in decreased water holding capacity and increased shear force compared to control and treatment 1 (p < 0.05). Furthermore, pH, red chromaticity (a*), yellowness index (b*), and luminance (L*) were unaffected among the four groups of sheep. In conclusion, the inclusion of up to 30% Rosa roxburghii Tratt residue had no adverse effects on growth performance, allowing for feed cost savings without impacting rumen fermentation parameters. Rosa roxburghii tratt residue also showed benefits in improving plasma protein efficiency and enhancing lipid metabolism, albeit with limited effects on meat quality. Considering its affordability, Rosa roxburghii Tratt residue presents a practical choice for low-cost diets, ensuring economic returns.

Responses of nutrient utilization, rumen fermentation and microorganisms to different roughage of dairy buffaloes

Dairy buffaloes are typically fed a high-forage, low-quality diet with high fiber. These conditions result in an inherent energy and protein inefficiency. In order to make full and rational use of feed resources and improve the production level and breeding efficiency of dairy buffaloes, the effects of various roughages on nutrient digestibility, ruminal fermentation parameters, and microorganisms in dairy buffaloes were studied in this experiment. Three ternary hybrid buffaloes, with an average body weight of 365 ± 22.1 kg, were selected and fitted with permanent rumen fistulas. They were fed six different diets, each consisting of 1 kg concentrate supplement and one of six types of roughage, including alfalfa hay (A diet), oat hay (O diet), whole corn silage (W diet), king grass (K diet), sugarcane shoot silage (S diet), and rice straw hay (R diet) according to an incomplete Latin square design of 3 × 6, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 was the official experimental period. During the prefeeding period, free feed intake for each roughage was determined, and during the experiment, the roughage was fed at 90% of the voluntary feed intake. Digestion and metabolism tests were carried out using the total manure collection method to determine the feed intake and fecal output of each buffalo, and to collect feed and fecal samples for chemical analysis. On day 15, rumen fluid samples were collected two hours after morning feeding to determine rumen fermentation parameters and bacterial 16 S rRNA high-throughput sequencing was performed. The results showed that DM and OM digestibility were greatest for the W diet and lowest for the S diet. The rumen pH of the O diet was significantly greater than that of the W diet. The concentration of rumen fluid NH3-N (mg/dL) increased with increased CP content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with increased NDF content but increased with increased NFC content. The relative abundances of Bacteroidetes, Firmicutes, and Spirochaetes were 57.03-74.84%, 14.29-21.86%, and 0.44-1.43% in the different quality roughage groups. Bacteroidetes were mainly Prevotellaceae1 and Rikenellaceae RC_gut_group with relative abundances of 30.17-45.75% and 3.23-7.82%. The relative abundance of Patescibacteria and Spirochaetes decreased with increasing roughage quality. These results provide a theoretical and practical basis for evaluating the nutritional value of dairy buffalo feed, utilizing feed resources, matching rations, feeding scientifically, and protecting animal health.

Effects of different dietary energy levels on growth performance, meat quality and nutritional composition, rumen fermentation parameters, and rumen microbiota of fattening Angus steers.

This study investigates the effects of varying energy levels in diets on Black Angus steers, focusing on growth performance, muscle composition, rumen microbial community, and their interrelationships. Twenty-seven Black Angus steers, aged approximately 22 months and weighing 520 ± 40 kilograms, were randomly divided into three groups: low-energy (LE), medium-energy (ME), and high-energy (HE). Each group consisted of nine individuals. The steers were fed diets with energy levels of 6.657 MJ/kg (LE), 7.323 MJ/kg (ME), and 7.990 MJ/kg (HE) following a 14-day pre-feeding period, with a subsequent 90-day main experimental phase. After the 90-day feeding period, both the HE and ME groups exhibited significantly higher average daily weight gain (ADG) compared to the LE group (p < 0.05). The feed-to-weight ratios were lower in the HE and ME groups compared to the LE group (p < 0.05). The HE group showed significantly higher crude fat content in the longissimus dorsi muscle compared to the LE group (p < 0.05), with total fatty acid content in the muscle surpassing that in the ME and LE groups (p < 0.05). As dietary energy levels increased, the diversity of the rumen microbial community decreased (p < 0.05), and significant differences in bacterial community structure were observed between the LE and HE groups (p < 0.05). The results suggest that higher dietary energy levels enhance growth performance and alter muscle composition in Black Angus steers, while also influencing the rumen microbial community. This study contributes to understanding optimal dietary strategies for finishing Angus cattle to improve beef quality, economic returns, and the development of standardized production procedures.

High deoxynivalenol and ergot alkaloid levels in wheat grain: effects on growth performance, carcass traits, rumen fermentation, and blood parameters of feedlot cattle

This study was designed to assess the impacts of a mixture of deoxynivalenol (DON) and ergot alkaloids (EAs) on growth performance, rumen function, blood parameters, and carcass traits of feedlot cattle. Forty steers (450 ± 6.0 kg) were stratified by weight and randomly allocated to 1 of 4 treatments; control-low (CON-L), control-high (CON-H) which contained low or high wheat screenings that lacked mycotoxins at the same level as the mycotoxin-low (MYC-L; 5.0 mg/kg DON, 2.1 mg/kg EA), and mycotoxin-high (MYC-H: 10 mg/kg DON, 4.2 mg/kg EA) diets that included wheat screening with mycotoxins. Steers were housed in individual pens for a 112-day finishing trial. Intake was 24.8% lower (P < 0.001) for MYC steers compared to CON steers. As a result, average daily gains of MYC steers were 42.1% lower (P < 0.001) than CON steers. Gain to feed ratio was also lower (P < 0.001) for MYC steers compared to CON steers. Platelets, alanine aminotransferase, globulins, and blood urea nitrogen were lower (P ≤ 0.008), and lymphocytes, glutathione peroxidase activity (GPx), and interleukin-10 (IL-10) were elevated (P ≤ 0.002) in MYC steers compared to CON steers. Hot carcass weights and backfat thickness were reduced (P < 0.001) in MYC steers, resulting in leaner (P < 0.001) carcasses and higher (P < 0.007) meat yield compared to CON steers. Results suggest that a mixture of DON and EAs negatively impacted health, performance, and carcass traits of feedlot steers, with the majority of this response likely attributable to EAs. However, more research is needed to distinguish the relative contribution of each mycotoxin to the specific responses observed.

Short- and long-term effects of different forage types supplemented in preweaning dairy calves on performance and milk production into first lactation

We investigated the short- and long-term effects of different forage types supplemented in preweaning dairy calves on growth performance, blood metabolites, rumen fermentation, bacterial community, and milk production during first lactation. Sixty healthy 1-mo-old female Holstein calves were blocked by birth date and body weight and randomly assigned to one of 3 groups (n = 20): normal milk and pelleted starter feeding (CON), supplemented with chopped oat hay [75.0 g/d/calf (dry matter (DM) basis); OAH], or alfalfa hay [75.0 g/d/calf (DM basis); ALF]. The forage supplementation started when calves were 30 d old (D1 of the experimental period) and ended when they were 73 d old (D44 of the experimental period when calves were weaned. Milk and feed intakes and fecal consistency scores were recorded daily. Growth performance, rumen fluid, and blood samples were collected bi-weekly. After weaning, all the calves were integrated with the same barn and diets. After calving, the milk production was recorded daily. During the experimental period, the OAH group had greater solid feed and total DM intakes and greater rumen pH than the CON group (P ≤ 0.04), but had lower forage intake and crude protein digestibility than the ALF group (P ≤ 0.04). The ALF group had higher rumen pH and blood β-hydroxybutyrate concentration (P ≤ 0.04), lower fecal score (P = 0.02), and greater ether extract digestibility (P = 0.02) than the CON group. The ALF and OAH groups had lower concentrations of ruminal total volatile fatty acids (P = 0.01). Still, the ALF group had a greater proportion of acetate and a relative abundance of cellulose degradation-related bacteria (Lachnoclostridium_1 and Oribacterium) and a lower relative abundance of inflammation-related bacteria (Erysipelotrichaceae_UCG-009) in the rumen compared with CON. Interestingly, the average milk production from 6 to 200 d in milk (DIM) was greater in the ALF group (P < 0.01) even though no significant effects were found on the rumen fermentation parameters and blood metabolites at 200 DIM. Generally, alfalfa hay supplementation in preweaning dairy calves had positive effects in the short- and long-term in terms of rumen development, health status, and future milk production.

Supplementation of Methionine Dipeptide Enhances the Milking Performance of Lactating Dairy Cows.

Methionine dipeptide (Met-Met) could improve milk protein synthesis in bovine epithelia mammary cells and lactating mice, while the effects of Met-Met on lactation performance, rumen fermentation and microbiota profile in lactating dairy cows have not been explored. For this reason, 60 Chinese lactating Holstein cows were allocated into three treatment groups: control group (CON), 6 g/d methionine dipeptide group (MM), and 6.12 g/d rumen-protected methionine dipeptide group (RPMM). The experiment lasted for 10 weeks to monitor lactation performance, plasma amino acid profile and rumen fermentation parameters and microbiota profile. Results showed that MM increased the energy-corrected milk (ECM), and RPMM increased both milk yield and ECM (p < 0.05). The milk protein concentration and yield were increased by MM and RPMM (p < 0.05). The rumen fermentation showed that RPMM increased total volatile fatty acids, acetate and valerate concentrations (p < 0.05). The relative abundance of Firmicutes, including Succiniclasticum, Selenomonas and Clostridium_XlVa, were enriched and the Prevotella was decreased by RPMM (p < 0.05). In summary, daily supplementing with 6 g of MM or RPMM in lactating dairy cows could improve milk yield and both percentage and yield of milk protein, and RPMM benefited the rumen fermentation and altered the bacterial composition. These results provided the first evidence that Met-Met supplementation can improve lactation performance of dairy cows.

Evaluating the dose-dependent effects of curcumin nano-micelles on rumen fermentation, nitrogen metabolism, and nutrient digestibility in heat-stressed fattening lambs: Implications for climate change and sustainable animal production.

Global warming threatens livestock production, especially in hot climates. This study evaluated the dose-dependent impacts of dietary curcumin nano-micelles (CNM) on rumen fermentation, nitrogen metabolism, and nutrient digestibility in heat-stressed fattening lambs. Thirty-two crossbred male lambs [ˆIle-de-France × (Dalagh × Romanov)] were utilized within the current study. The initial weight of lambs was documented as averaged by 31.2 ± 1.55 kg, while they were in their 4th to 5th months of age. Animals were fed increasing doses of dietary CNM (0, 20, 40, and 80 mg/day) over 97 days, under severe heat stress conditions with average temperature-humidity index (THI) of 24.5. Quadratic improvements (p < 0.01) occurred in weight gain, average daily gain (ADG), and feed conversion ratio (FCR) by 28.7%, 27.4%, and 23.9%, respectively, in the T40 group compared to the control. Additionally, T40 increased fiber digestion by 2.8% (p < 0.05). Furthermore, T40 quadratically improved parameters of rumen fermentation, including concentrations of NH3-N (p < 0.05), total volatile fatty acids (TVFA; p < 0.01), acetate (p < 0.05), and iso-valerate (p < 0.05), by 13.9%, 12.5%, 15.0%, and 43.5%, respectively, compared to the control. Quadratic increases were also observed in nitrogen balance (p < 0.05) and microbial protein synthesis (p < 0.01) by 19.8% and 37.6%, respectively, in the T40 group. Quadratic models estimated optimal CNM levels between 41.5 and 48.6 mg/day for multiple parameters. These findings indicate CNM at dose level of 40 mg/day could benefit heat-stressed lambs through enhanced rumen function and microbiota. Further research should refine ideal dosing for various species and production phases as higher levels adversely impacted fiber digestibility. Overall, CNM shows promise as a sustainable nutritional intervention for livestock production facing global warming.

Dietary copper levels affect mineral absorbability, rumen microbial composition and metabolites of the grazing Mongolian sheep

Copper (Cu) is a critical limiting factor in grazing livestock production in Inner Mongolia. This study investigated the effects of Cu-deficient and Cu-supplemented diets on production metrics, nutrient digestion and absorption, ruminal microbiota, and metabolites in grazing Mongolian sheep. A total of 28 individually-housed Mongolian sheep were randomly assigned to a Cu-deficient feeding group (LCu) and a Cu-deficient feeding control group (LCG), supplemented with a multi-nutrient salt containing 0 mg Cu and 14.3 mg Cu, respectively, for 53 continuous days. Following this, a 7-day digestion test was conducted, after which seven sheep from each group were randomly slaughtered. The remaining sheep in LCu and LCG transitioned to a Cu-supplemented feeding group (SCu) and a Cu-supplemented feeding control group (SCG), receiving multi-nutrient salts with 43.0 mg Cu and 14.3 mg Cu, respectively. This phase entailed a 34-day diet acclimatization period, a 7-day digestion test, and eventual slaughter. The LCu diet significantly decreased the ruminal Cu and sulfur (S) content, as well as Cu apparent absorbability, compared to the LCG group (P<0.05). Conversely, SCu significantly increased the ruminal Cu content and the apparent absorbability of phosphorus (P), S, potassium (K), calcium (Ca), manganese (Mn), iron (Fe), Cu and zinc (Zn) compared to the SCG group (P<0.05). Amplicon sequencing analysis revealed a significant downregulation of Alistipes and Barnesiella (P<0.05) in the LCu group. Metabolomic analyses supported an elevation in ruminal citrulline and L-ornithine levels, affecting amino acid metabolic pathways in the LCu group (P<0.05). In the SCu group, there was a significant increase in the relative abundance of Saccharofermentans and Ruminococcus (P<0.05), with metabolomic analysis revealed elevated levels of nucleic acid and purine analog affecting purine metabolic pathways (P<0.05). Notably, neither treatment had a significant impact production metrics, rumen fermentation parameters, or the apparent digestibility of crude protein, acid detergent fiber and neutral detergent fiber (P>0.05). In conclusion, a Cu-deficient diet impairs Cu absorption and nutrient catabolism in grazing Mongolian sheep, while Cu supplementation effectively alleviated these deficiencies and enhances the absorption of various minerals.

Intensive feeding alters the rumen microbiota and its fermentation parameters in natural grazing yaks.

Amidst the challenging environmental conditions characterized by low oxygen levels and cold temperatures on the plateau, alterations in nutrient supply emerge as pivotal factors influencing the survival and reproduction of yaks. Intensive feeding stands out as a substantial mechanism for nutrient provision, initiating discernible changes in the host's rumen flora. Within the extreme natural conditions prevailing in the plateau area of northwest Yunnan, China, there exists a con-strained comprehension of the variations in rumen microflora, fermentation parameters, and growth responses exhibited by yaks subjected to intensive feeding. This study employs 16S rRNA and ITS sequencing methods to scrutinize the rumen flora of yaks engaged in both natural grazing (G) and intensive feeding (F) on the plateau. The outcomes unveil that, during the severe winter season, yaks adeptly modulate the abundance and diversity of rumen flora in response to dietary modifications under intensive feeding, aiming to optimize the efficient utilization of dietary fiber and energy. Principal Coordinate Analysis (PCoA) illustrates a substantial alteration in the rumen microbial community of naturally grazing yaks when exposed to intensive feeding. The natural grazing group manifests a higher prevalence of Firmicutes and Bacteroidetes, while the intensive feeding group exhibits heightened levels of Prevotella in the rumen. The Rikenellaceae _ RC9 _ gut_ group, associated with mycobacteria, prevails more abundantly in the natural grazing setting. PICRUSt2 analysis indicates that intensive feeding induces bacterial gene overexpression linked to protein metabolism. Rumen fungi showcase heightened diversity under intensification. Intensive feeding results in an augmented abundance of non-fiber-degrading bacteria and semi-fiber-degrading bacteria, accompanied by elevated concentrations of Volatile Fatty Acids (VFA). These findings yield novel insights into the shifts in the rumen microflora of yaks acclimated to intensive feeding in high-altitude environments, provide an important reference for the nutritional regulation of supplemental feeding of natural grazing yaks in the cold season, ultimately contributing to their enhanced growth.

16S amplicon sequencing and untargeted metabolomics reveal changes in rumen microorganisms and metabolic pathways involved in the reduction of methane by cordycepin

As a major contributor to methane production in agriculture, there is a need for a suitable methane inhibitor to reduce ruminant methane emissions and minimize the impact on the climate. This work aimed to explore the influence of cordycepin on rumen fermentation, gas production, microbiome and their metabolites. A total of 0.00, 0.08, 0.16, 0.32, and 0.64 g L-1 cordycepin were added into fermentation bottles containing 2g total mixed ration for in vitro ruminal fermentation, and then the gas produced and fermentation parameters were measured for each bottle. Samples from the 0.00 and 0.64 g L-1 cordycepin addition were selected for 16S rRNA gene sequencing and metabolome analysis. The result of this experiment indicated that the addition of cordycepin could linearly increase the concentration of total volatile fatty acid, ammonia nitrogen, the proportion of propionate, valerate, and isovalerate, and linearly reduce ruminal pH and methane, carbon dioxide, hydrogen and total gas production, as well as the methane proportion, carbon dioxide proportion and proportion of butyrate. In addition, there was a quadratic relationship between hydrogen and cordycepin addition. At the same time, the relative abundance of Succiniclasticum, Prevotella, Rikenellaceae_RC9_gut_group, NK4A214_group, Christensenellaceae_R_7_group, unclassified_F082, Veillonellaceae_UCG_001, Dasytricha, Ophryoscolex, Isotricha, unclassified_Eukaryota, Methanobrevibacter, and Piromyces decreased significantly after adding the maximum dose of cordycepin. In contrast, the relative abundance of Succinivibrio, unclassified_Succinivibrionaceae, Prevotellaceae_UCG_001, unclassified_Lachnospiraceae, Lachnospira, Succinivibrionaceae_UCG_002, Pseudobutyrivibrio, Entodinium, Polyplastron, unclassified_Methanomethylophilaceae, Methanosphaera, and Candidatus_Methanomethylophilus increased significantly. Metabolic pathways such as biosynthesis of unsaturated fatty acids and purine metabolism and metabolites such as arachidonic acid, adenine, and 2′-deoxyguanosine were also affected by the addition of cordycepin. Based on this, we conclude that cordycepin is an effective methane emission inhibitor that can change the rumen metabolites and fermentation parameters by influencing the rumen microbiome, thus regulating rumen methane production. This experiment may provide a potential theoretical reference for developing Cordyceps byproduct or additives containing cordycepin as methane inhibitors.

Effects of Garlic Oil and Cinnamaldehyde on Sheep Rumen Fermentation and Microbial Populations in Rusitec Fermenters in Two Different Sampling Periods.

Garlic oil (GO) and cinnamaldehyde (CIN) have shown potential to modify rumen fermentation. The aim of this study was to assess the effects of GO and CIN on rumen fermentation, microbial protein synthesis (MPS), and microbial populations in Rusitec fermenters fed a mixed diet (50:50 forage/concentrate), as well as whether these effects were maintained over time. Six fermenters were used in two 15-day incubation runs. Within each run, two fermenters received no additive, 180 mg/L of GO, or 180 mg/L of CIN. Rumen fermentation parameters were assessed in two periods (P1 and P2), and microbial populations were studied after each of these periods. Garlic oil reduced the acetate/propionate ratio and methane production (p < 0.001) in P1 and P2 and decreased protozoal DNA concentration and the relative abundance of fungi and archaea after P1 (p < 0.05). Cinnamaldehyde increased bacterial diversity (p < 0.01) and modified the structure of bacterial communities after P1, decreased bacterial DNA concentration after P2 (p < 0.05), and increased MPS (p < 0.001). The results of this study indicate that 180 mg/L of GO and CIN promoted a more efficient rumen fermentation and increased the protein supply to the animal, respectively, although an apparent adaptive response of microbial populations to GO was observed.

Impact of combined management strategies of monensin and virginiamycin in high energy diets on ruminal fermentation and nutrients utilization.

Feed additives such as monensin (MON) and virginiamycin (VM) are commonly utilized in feedlot diets to enhance rumen fermentation. Nevertheless, the precise effects of combining MON and VM during specific feedlot periods and the advantages of this combination remain unclear. This study was designed to investigate the effects of withdrawal of MON when associated with VM during the adaptation and finishing periods on ruminal metabolism, feeding behavior, and nutrient digestibility in Nellore cattle. The experimental design was a 5 × 5 Latin square, where each period lasted 28 days. Five rumen-cannulated Nellore yearling bulls were used (414,86 ± 21,71 kg of body weight), which were assigned to five treatments: (1) MON during the entire feeding period; (2) VM during the entire feeding period; (3) MON + VM during the adaptation period and only VM during the finishing period 1 and 2; (4) MON + VM during the entire feeding period; (5) MON + VM during the adaptation and finishing period 1 and only VM during the finishing period 2. For the finishing period 1, animals fed T3 had improved potential degradability of dry matter (p = 0.02). Cattle fed T3 and T5 had the highest crude protein degradability when compared to animals receiving T2 (p = 0.01). Animals fed T2 and T3 had reduced the time (p < 0.01) and area under pH 6.2 (p = 0.02). Moreover, animals fed T4 had greater population of protozoa from the genus Diplodinium (p = 0.04) when compared to those from animals fed T2, T3 and T5. For the finishing period 2, animals fed T3 had greater starch degradability when compared to animals receiving T4 and T5 (p = 0.04). Animals fed T3, T4 and T5 had increased the duration of time in which pH was below 5.6 (p = 0.03). The area under the curve for ruminal pH 5.2 and pH 5.6 was higher for the animals fed T3 (p = 0.01), and the area under pH 6.2 was higher for the animals fed T3 and T5 (p < 0.01) when compared to animals receiving T2. There is no substantial improvement on the rumen fermentation parameters by the concurrent utilization of MON and VM molecules, where the higher starch and protein degradability did not improve the rumen fermentation.

Effects of allicin addition on growth performance, rumen microbiome, and ruminal epithelial proteome of high-grain-fed goats

It is well known that allicin has anti-bacterial, anti-oxidation, and anti-inflammatory biological functions. However, there is little information on whether allicin has beneficial effects on ruminants fed a high-grain (HG) diet. This study was conducted to investigate the effects of allicin addition on growth performance, ruminal microbes in different rumen ecological niches (REN), and the rumen epithelial (RE) proteome in fattening goats fed a HG diet. Twenty-four Anhui white goats were randomly allocated to three dietary treatments: control diet (CON, n = 8), high-grain diet (HG, n = 8), and high-grain diet + allicin (HGA, n = 8). After 56 days, blood, rumen fluid (RL), rumen solid (RS), and RE tissue were sampled for further analysis. Compared with the HG diet, the addition of allicin decreased (P < 0.05) the DMI, with no effects (P > 0.05) on daily weight gain and rumen fermentation parameters. The malondialdehyde concentrations were lower (P < 0.05) in the HGA group than in the HG group. The HGA group had a higher activity of glutathione peroxidase in the rumen epithelium than the HG group. The alpha diversity in different REN in the HGA group was higher (P < 0.05) than that in the HG group. Compared to the HG group, the HGA group had higher relative abundances of Lachnospiracea_incertae_sedis, Ruminobacter, and Bifidobacterium (P < 0.05), and lower relative abundances of Methanomassiliicoccus (P < 0.05). The addition of allicin helped mitigate or reverse the differences between the HG diet and the CON diet at the genus level in different RENs. Proteomic analysis of the rumen epithelium showed that proteins involved in cell junction and immune function were downregulated, whereas those involved in oxidative stress and inflammatory reactions were upregulated in the HG group in comparison with the CON group. Compared with the HG group, the addition of allicin increases the abundance of proteins involved in cell junction and immune function and decreases those of proteins involved in oxidative stress and inflammatory reactions. Our findings indicate that the addition of allicin can improve the antioxidant capacity, modify the rumen microbial composition, alleviate the damage to the rumen epithelium cell junction, and protect the rumen epithelium of goats fed a HG diet.

Mechanistic insights into inositol-mediated rumen function promotion and metabolic alteration using in vitro and in vivo models.

Inositol is a bioactive factor that is widely found in nature; however, there are few studies on its use in ruminant nutrition. This study investigated the effects of different inositol doses and fermentation times on rumen fermentation and microbial diversity, as well as the levels of rumen and blood metabolites in sheep. Rumen fermentation parameters, microbial diversity, and metabolites after different inositol doses were determined in vitro. According to the in vitro results, six small-tailed Han sheep fitted with permanent rumen fistulas were used in a 3 × 3 Latin square feeding experiment where inositol was injected into the rumen twice a day and rumen fluid and blood samples were collected. The in vitro results showed that inositol could increase in vitro dry matter digestibility, in vitro crude protein digestibility, NH3-N, acetic acid, propionic acid, and rumen microbial diversity and affect rumen metabolic pathways (p < 0.05). The feeding experiment results showed that inositol increased the blood concentration of high-density lipoprotein and IgG, IgM, and IL-4 levels. The rumen microbial composition was significantly affected (p < 0.05). Differential metabolites in the rumen were mainly involved in ABC transporters, biotin metabolism, and phenylalanine metabolism, whereas those in the blood were mainly involved in arginine biosynthesis and glutathione and tyrosine metabolism. In conclusion, inositol improves rumen function, affects rumen microorganisms and rumen and blood metabolites and may reduce inflammation, improving animal health.

Effects of indigenous &lt;i&gt;Saccharomyces cerevisiae&lt;/i&gt; on intake, growth, gut histology, and serum biomarkers in pre-weaned Lohi lambs

The purpose of this study was to determine the comparative efficacy of locally-produced yeastnto commercial yeast on growth nperformance, serum biomarkers, and gut histology. Thirty pre-weanednmale Lohi lambs were divided into; 1) C (Control; starter diet nwith no supplement), 2) CY (starter dietnwith ewe milk supplemented with 1 g/animal/day commercial yeast), and 3) LY (starter dietnsupplemented with 1 g/animal/day local yeast). Animals were housed individually and fed a starter dietnand orts were weighed ndaily. Dry matter intake (DMI) was determined daily while the body weights werendetermined on a weekly basis. At the end of the trial, nblood samples were collected and analysed fornblood urea nitrogen (BUN), glucose, β-Hydroxybutyrate (BHBA), and non-esterified fatty nacids (NEFA),nwhile ruminal fluid and tissues were collected for rumen fermentation parameters andnhistomorphometry. The results nrevealed that the DMI and average daily weight gain (ADWG) werenhigher in CY and LY compared to C. The feed efficiency was also nbetter in CY and LY lambs comparednto C lambs. The BHBA, BUN, total proteins (TP), cholesterol, creatinine, blood glucose, and tissuenhistomorphometry were similar in LY and CY supplementation. In conclusion, supplementation with LYnproduced comparable nresults to the CY.