Dietary saccharin sodium supplementation improves the production performance of dairy goats without residue in milk in summer.

The purpose of this study was to investigate the effects of dietary saccharin sodium supplementation on production performance, serum biochemical indicators, and rumen fermentation of dairy goats in summer. Twelve Guanzhong dairy goats with similar body weight, days in milk, and milk yield were randomly divided into two dietary treatments: (1) CON: basal diet; (2) SS: basal diet + 150 mg/kg saccharin sodium on the basis of dry matter. The experiment lasted 35 d, including 7 d for adaptation and 28 d for dietary treatments, sampling and data collection. Each dairy goat was housed individually in a clean separate pen with ad libitum access to diet and water. The goats fed SS diet had increased dry matter intake (DMI; P = 0.037), 4% fat corrected milk yield (P = 0.049), energy corrected milk yield (P = 0.037), milk protein yield (P = 0.031), and total solids yield (P = 0.036). Serum activity of aspartate aminotransferase (P = 0.047) and concentrations of 70-kDa heat shock protein (P = 0.090), malondialdehyde (P = 0.092), and total protein (P = 0.057) were lower in goats fed SS diet than those fed CON diet. Supplementation of saccharin sodium tended to increase activity of glutathione peroxidase in serum (P = 0.079). The concentrations of rumen total volatile fatty acid (P = 0.042) and butyrate (P = 0.038) were increased by saccharin sodium supplementation. Dietary supplementation of saccharin sodium increased the relative abundance of Lachnobacterium (P = 0.022), Pseudoramibacter (P = 0.022), Shuttleworthia (P = 0.025), and Syntrophococcus (P = 0.037), but reduced the relative abundance of Prevotella_1 (P = 0.037) and Lachnospiraceae_UCG_008 (P = 0.037) in rumen. Saccharin sodium was observed in feces and urine of goats fed diet supplemented with saccharin sodium, but saccharin sodium was undetectable in the milk of goats receiving SS diet. In conclusion, administration of saccharin sodium was effective in increasing fat and energy corrected milk yield by increasing DMI and improving rumen fermentation and antioxidant capacity of dairy goats in summer. In addition, saccharin sodium residue was undetectable in the milk.

The use of microencapsulated banana flower powder pellet on in vitro ruminal fermentation, digestibility, microbial diversity, and methane production.

Ruminant animals constitute major contributors to greenhouse gas (GHG) emissions and play an important part in sustainable agricultural systems. A bioactive compound (BC) with antibacterial properties was utilized to inhibit rumen methanogens and decrease ruminant methane emissions. The bio efficacy of ruminant nutrition was frequently employed using a new technology through microencapsulation technique to produce stable products. The microencapsulated banana flower powder pellet (mBAFLOP) powder was used as a BC in the diets. Consequently, this study aimed to evaluate the effects of mBAFLOP supplementation on in vitro gas production kinetics, rumen fermentation, microbial population, and methane production. A completely randomized design (CRD) was used to randomly assign respective treatments at 0, 1, 2, and 3% of the total dry matter (DM) substrate. Ruminal pH, in vitro dry matter degradability and volatile fatty acid profile both at 12, and 24 h were not negatively affected by supplementation with mBAFLOP. The supplemented mBAFLOP (3% of total DM substrate) resulting in ruminal ammonia-nitrogen concentrations was linearly increased (P < 0.01) different among treatments, while methane production was reduced when compared with other treatment (quadratic effect, P < 0.05). Moreover, Ruminococcus flavefaciens was increased when the proportion of mBAFLOP supplement was increased. Furthermore, there was a linear effect (P < 0.05) of decreasing Methanobacteriales in the rumen with increased levels of mBAFLOP supplementation. Based on this study, the use of mBAFLOP at 3% could enhance NH3N concentration and cellulolytic bacteria especially Ruminococcus flavefaciens was increased. Furthermore, supplementation with mBAFLOP decreased methane production. Therefore, a possible dietary plant-based bioactive compound, mBAFLOP supplementation cloud enhances rumen fermentation and mitigates methane production.

Effects of High-Grain Diet on Performance, Ruminal Fermentation, and Rumen Microbial Flora of Lactating Holstein Dairy Cows.

The objectives of the current study were to evaluate the fluctuations in production performance, rumen fermentation, and microbial community in lactating dairy cows fed a high-grain diet (HG). In this study, 16 healthy Holstein lactating dairy cattle with similar milk yields of 16.80 ± 4.30 kg/d, days in milk 171.44 ± 23.25 days, and parity 2.2 ± 1.5 times were selected and randomly allocated into two groups. One group was fed a low-grain diet (LG; 40% concentrate, DM basis; n = 8), and the other group was fed a high-grain diet (HG; 60% concentrate, DM basis; n = 8). The experiment lasted 6 weeks, including 1 week for adaptation. The experimental results showed that the milk fat content in the milk of lactating cows in the HG group was significantly reduced (p < 0.05), and the milk urea nitrogen (MUN) content showed an increasing trend (0.05 < p < 0.10) compared with the LG group. Compared with the LG group, rumen fluid pH was significantly decreased after feeding a high-grain diet, and contents of total volatile fatty acids (TVFA), acetate, propionate, and butyrate were significantly increased (p < 0.05). The acetate/propionate significantly decreased (p < 0.05). HG group significantly increased the abundance of Prevotella and Bacteroides in rumen fluid while significantly reducing the abundance of Methanobrevibacter and Lachnospiraceae ND3007_group (p < 0.05). Microorganisms with LDA scores > 2 were defined as unique, with the bacterial genus Anaerorhabdus_furcosa_group identified as a biomarker for the LG group, and the unique bacterial genus in the HG group were Prevotella, Stenotrophomonas, and Xanthomonadaceae. The prediction results of microbial function showed that a total of 18 KEGG differential pathways were generated between the two treatment groups, mainly manifested in metabolic pathways, signal transduction, and the immune system. In conclusion, the HG group promoted rumen fermentation by altering the microbial composition of lactating cows. Our findings provide a theoretical basis for the rational use of high-grain diets to achieve high yields in intensive dairy farming.

Effects of Dietary Energy Levels on Growth Performance, Nutrient Digestibility, Rumen Barrier and Microflora in Sheep.

Dietary energy is crucial for ruminants' performance and health. To determine optimal dietary energy levels for growing sheep, we evaluated their growth performance, nutrient digestibility, rumen fermentation, barrier function, and microbiota under varying metabolic energy (ME) diets. Forty-five growing Yunnan semi-fine wool sheep, aged 10 months and weighing 30.8 ± 1.9 kg, were randomly allocated to five treatments, each receiving diets with ME levels of 8.0, 8.6, 9.2, 9.8 or 10.4 MJ/kg. The results showed that with increasing dietary energy, the average daily gain (ADG) as well as the digestibility of dry matter (DM) and organic matter (OM) increased (p < 0.05), while the feed conversion ratio (FCR) decreased linearly (p = 0.01). The concentration of total VFA (p = 0.03) and propionate (p = 0.01) in the rumen increased linearly, while rumen pH (p < 0.01) and the acetate-propionate ratio (p = 0.01) decreased linearly. Meanwhile, the protein contents of Claudin-4, Claudin-7, Occludin and ZO-1 as well as the relative mRNA expression of Claudin-4 and Occludin also increased (p < 0.05). In addition, rumen bacterial diversity decreased with the increase of dietary energy, and the relative abundance of some bacteria (like Saccharofermentans, Prevotella and Succiniclasticum) changed. In conclusion, increasing dietary energy levels enhanced growth performance, nutrient digestibility, rumen fermentation, and barrier function, and altered the rumen bacterial community distribution. The optimal dietary ME for these parameters in sheep at this growth stage was between 9.8 and 10.4 MJ/kg.

An Automated Sprinkler Cooling System Effectively Alleviates Heat Stress in Dairy Cows.

(1) Background: Heat stress detrimentally restricted economic growth in dairy production. In particular, the cooling mechanism of the spraying system effectively reduced both environmental and shell temperatures. This study was designed to investigate the underlying modulatory mechanism of an automatic cooling system in alleviating heat-stressed dairy cows. (2) Methods: A total of 1208 multiparous dairy cows was randomly allocated into six barns, three of which were equipped with automatic sprinklers (SPs), while the other three were considered the controls (CONs). Each barn was considered a replicate. (3) Results: Body temperatures and milk somatic cell counts significantly decreased, while DMI, milk yield, and milk fat content significantly increased under SP treatment. Rumen fermentability was enhanced, embodied by the increased levels of total VFA, acetate, propionate, and butyrate after SP treatment. The rumen microbiota results showed the relative abundances of fiber-degrading bacteria, including the Fibrobacters, Saccharofermentans, Lachnospira, Pseudobutyrivibrio, Selenomonas, and Succinivibrio, which significantly increased after receiving the SP treatment. (4) Conclusions: This study demonstrated that SP effectively alleviated heat stress and improved production performances and milk quality through modulating the rumen microbiota composition and fermentation function of dairy cows.

In vitro rumen fermentation characteristics of bakery by-products containing high starch and sugar.

The objectives of this study were to evaluate the nutritional characteristics of bakery by-products (castella, pancake, baumkuchen) and their effect on rumen fermentation in vitro as compared with steam-flaked corn and barley as human-edible grains. The fermentation pattern of sugar and starch as pure components was also investigated. Additionally, rumen pH was evaluated using a low-capacity buffer. Bakery by-products contained high sugar (212-590 g/kg DM) and starch (262-545 g/kg DM). Castella exhibited the highest sugar content, whereas pancake and baumkuchen were rich in starch and ether extract within bakery by-products, respectively. The gas production rate at the early phase of incubation was higher in bakery by-products than in grains, and the highest in castella among all feeds. Bakery by-products produced higher total organic acids and propionate than grains. Bakery by-products also exhibited a lower rumen pH than grains during twenty-four hours of incubation with a low-capacity buffer. As pure components, sucrose showed a higher gas production rate and lower pH than starch. Overall, compared with grains, bakery by-products have the potential not only to supply more energy to ruminants but also decrease rumen pH because sugar and starch in bakery by-products ferment rapidly and produce higher organic acids in the rumen.

Impacts of increasing levels of salt on intake, digestion, and rumen fermentation with beef cattle consuming low-quality forages.

The objectives of this study were to evaluate the levels of supplemental salt on low-quality forage intake, water intake, dry matter digestibility, and rumen fermentation. Six ruminally cannulated, Angus crossbred heifers (14 mo of age; 449 kg ± 24 kg BW) were used in a dual 3 × 3 Latin square design. The heifers were housed in individual stalls with two animals assigned to each treatment per period. Salt treatments were mixed into a protein supplement of 50% cracked corn and 50% soybean meal and fed at 0.3% of shrunk BW. Salt treatments consisted of: 1) control, no salt (CON), 2) 0.05% of BW salt (LOW), and 3) 0.1% of BW salt (HIGH). Chopped, low-quality (CP = 7.4%; NDF = 64.2%), grass hay was used as the base ration and was provided daily at 120% of the average daily intake of the previous 3 days. Each period included a 14-day diet adaptation, 6 days of sample collection, 1 day collection of rumen fluid samples for ruminal and microbial profiles. Individual forage dry matter intake, water intake, and dry matter digestibility were measured during the 6-day collection period. Rumen pH, ammonia levels, and VFA concentrations were measured during the 1-day ruminal profile. Rumen DM and liquid fill were determined with a 5-hour post feeding rumen evacuation. Supplemental salt had no influence on forage intake (P = 0.19) expressed on a kg/day basis yet tended to decrease linearly (P = 0.06) with increasing levels of salt when expressed on a grams/kg body weight basis. Dry matter digestibility was not influenced by salt levels (P > 0.05), but DM fill tended to increase linearly with increasing salt levels (P = 0.06). Water intake and liquid fill, however, increased linearly with increasing level of salt (P < 0.01) with an 18.9% increase in water intake and 17.0% increase in liquid fill compared to control animals. Ruminal pH and ammonia levels both decreased linearly with increasing salt (P < 0.01). Acetate concentration and acetate: propionate ratio increased linearly with increasing levels of salt (P < 0.01). In contrast, isobutyrate and butyrate concentrations decreased linearly with increasing levels of salt (P < 0.01). Our research suggests that increasing levels of salt tends to influence dry matter intake, DM fill, liquid kinetics, and rumen fermentation characteristics. Results from this research provides additional information on how salt-limited supplements may impact beef cattle consuming low-quality forage diets.

Effects of 5-Aminolevulinic Acid Supplementation on Gas Production, Fermentation Characteristics, and Bacterial Community Profiles In Vitro.

To investigate the effect of 5-aminolevulinic acid (5-ALA) on in vitro rumen gas production, fermentation characteristics, and bacterial community profiles, five levels of 5-ALA (0, 100, 500, 1000, and 5000 mg/kg DM) were supplemented into a total mixed ration (concentrate/forage = 40:60) as substrate in an in vitro experiment. Results showed that as the supplementation level of 5-ALA increased, asymptotic gas production (b) decreased linearly and quadratically (p < 0.01) while the dry matter degradation rate increased quadratically (p < 0.01). Meanwhile, the propionate concentration of 72 h incubation fluid increased linearly (p = 0.03) and pH value increased linearly and quadratically (p < 0.01), while the concentrations of butyrate, isobutyrate, valerate, isovalerate, and NH3-N and the ratio of acetate/propionate (A/P) decreased linearly and quadratically (p < 0.05). There was no significant difference in any alpha diversity indices of bacterial communities among the various 5-ALA levels (p < 0.05). PCoA and PERMANOVA analysis revealed that the bacterial profiles showed a statistical difference between the treatment 5-ALA at 1000 mg/kg DM and the other levels except for 5000 mg/kg DM (p < 0.05). Taxonomic classification revealed a total of 18 and 173 bacterial taxa at the phylum and genus level with relative abundances higher than 0.01% in at least half of the samples, respectively. LEfse analysis revealed that 19 bacterial taxa were affected by 5-ALA levels. Correlation analysis showed that Actinobacteriota was positively correlated with the gas production parameter b, the ratio of A/P, and the concentration of butyrate, isovalerate, and NH3-N (p < 0.05) and negatively correlated with pH (p < 0.05). WPS-2 exhibited a negative correlation with the gas production parameter b, the ratio of A/P, and the concentration of butyrate, valerate, isobutyrate, isovalerate, and NH3-N (p < 0.05), along with a weaker positive correlation with pH (p = 0.04). The Bacteroidales BS11 gut group was negatively correlated with the concentration of propionate but positively correlated with gas production parameter b and the concentration of butyrate and NH3-N (p < 0.05). The Lachnospiraceae NK3A20 group was found to have a positive correlation with gas production parameter b, the ratio of A/P, and the concentration of butyrate, isobutyrate, isovalerate, valerate, total VFA, and NH3-N (p < 0.05), but a highly negative correlation with pH (p < 0.01). Differential metabolic pathways analysis suggested that metabolic pathways related to crude protein utilization, such as L-glutamate degradation VIII (to propanoate), L-tryptophan degradation IX, and urea cycle, increased with 5-ALA levels. In summary, including 5-ALA in the diet might improve energy and protein utilization by reducing the abundance of Actinobacteriota, the Bacteroidales BS11 gut group, the Lachnospiraceae NK3A20 group, and certain pathogenic bacteria and increasing the abundance of WPS-2.

Nano-encapsulation of essential amino acids: ruminal methane, carbon monoxide, hydrogen sulfide and fermentation.

This study aimed to evaluate the effect of nano-encapsulation of four essential amino acids (AA), threonine, methionine, tryptophan, and lysine on in vitro ruminal total gas, methane, carbon monoxide, and hydrogen sulfide production as well as the rumen fermentation profile in cattle. The highest (P < 0.001) rate and asymptotic gas production after 48 h of incubation was observed in the diets that had threonine, followed by lysine, methionine, and tryptophan. Asymptotic methane gas production decreased in the following order: threonine > lysine > tryptophan > methionine (P < 0.0001) and the rate of production per hour followed the same trend (P = 0.0259). CH4 parameters showed that in 4 h, 24 h, and 48 h of incubation the lowest methane production was obtained in the diet with methionine (P < 0.05) and the highest one in diet supplemented with threonine. Methane fractions showed that methionine-containing diets resulted in more (P < 0.05) metabolizable energy versus methane, followed by tryptophan-containing, and then lysine-containing diets. Methionine-fortified diets seem to be the most eco-friendly among those studied regarding methane output. However, based on methane, CO, and H2S output as well as the rumen fermentation profile nano-encapsulated lysine is recommended for use in ruminant nutrition.

Hydroponic fodder as alternative feeds for ruminants to reduce ruminal methane emissions: an in vitro study.

Malate, a precursor in the ruminal propionate production pathway, competes with methanogenesis for metabolic hydrogen, offering a way to reduce ruminal methane (CH4) production in ruminants. However, cost considerations hinder widespread use of malate in ruminant diets. An alternative approach involves utilizing transient malate levels generated during seed germination via the glyoxylate cycle. This study investigated the methane-mitigating potential of malate-containing hydroponic fodder. Fodder samples with peak malate concentrations from alfalfa, forage pea, Italian ryegrass, rye, soybean, triticale, and wheat during germination were subjected to in vitro rumen fermentation using the Hohenheim gas test. The basal diet of in vitro fermentation comprised 40% grass silage, 40% maize silage, 15% hay, and 5% concentrate on a dry matter basis, with nutritional characteristics including 42.1% neutral detergent fiber (NDF), 25.0% acid detergent fiber, 14.0% starch, 12.7% crude protein, and 3.5% ether extract (EE), on a dry matter basis. Experimental treatments were fodder inclusion involved replacing 20% of the basal diet (20R), and additionally, 100% replacement of the silages with alfalfa d 10 and rye d 9 (SR), the 2 high-malate fodders. Reductions in CH4 production were observed with soybean (20R, 6.7% reduction), alfalfa (20R, 6.6% reduction), and increased with rye (20R, 6.3% increase). In the setup replacing silages with high-malate fodders (SR), alfalfa decreased CH4 production (17.7%) but increased ammonia (174%), while rye increased CH4 production (35.8%). Organic matter digestibility increased with SR rye (12.6%). Marginal effects of dietary variables were analyzed in a Generalized Additive Model. A negative relationship between dietary malate content and CH4 production was observed, whereas dietary NDF and starch content were positive correlated with CH4 production. In conclusion, malate within the hydroponic fodder could potentially reduce CH4 emissions in ruminants. However, achieving sufficient efficacy requires high malate content. Additionally, use of hydroponic fodder may increase the risk of nitrogen emissions. Animal studies are required for further investigation.

Nicotinamide benefited amino acid metabolism and rumen fermentation pattern to improve growth performance of growing lambs.

Objective: Nicotinamide (NAM) is easily degraded in the rumen, the rumen-protected NAM (RPN) supplementation might enable the use of NAM in ruminants. This study aimed to elucidate the effects of RPN supplementation on growth performance, rumen fermentation, antioxidant status and AA metabolism in growing lambs. Methods: A total of 128 healthy and similar lambs (21.3 ± 0.28 kg, 70 ± 6.3 days of age) were allotted to 1 of 4 groups. The treatments were 0, 0.5, 1 and 2 g/d RPN supplementation. The RPN products (50% bioavailability) were fed at 0700 h every day for 12 weeks. All lambs were fed the same pelleted total mixed rations to allow ad libitum consumption and had free access to water. Results: The RPN tended to increase the average daily gain and feed efficiency. The tendencies of RPN × Day interaction were found for dry matter intake during the entire study (P = 0.078 and 0.073, respectively). The proportions of acetic acid, isobutyric acid and isovaleric acid were decreased, whereas the proportions of propionic acid and valeric acid were increased (P < 0.05). The ratio of acetic acid to propionic acid was decreased (P < 0.05). Moreover, the antioxidative status was enhanced and the glucose concentration was increased by RPN (P < 0.05). In addition, 17 amino acids (AAs) were detected in plasma, of which 11 AAs were increased by RPN (P < 0.05). Plasma metabolomics analysis identified 1395 compounds belonging to 15 classes, among which 7 peptides were significantly changed after RPN supplementation. Conclusion: Overall, the results suggested that RPN supplementation favoured the rumen fermentation pattern to propionic acid-type with benefited glucose metabolism, enhanced antioxidant capacity, and changed the AA and small peptide metabolism. This study provides a new perspective for studying the relationship between vitamin and AA metabolism.

Impact of ginger powder (Zingiber officinale) supplementation on the performance, biochemical parameters, antioxidant status, and rumen fermentation in Ossimi rams.

Background and Aim: Ginger (Zingiber officinale) has great potential as a growth promoter and immunostimulant in ruminant nutrition. This study assessed the impact of ginger powder supplementation on Ossimi rams' rumen fermentation, biochemical parameters, and antioxidant levels. Materials and Methods: Fifteen Ossimi rams, aged 10 ± 1.3 months and weighing 30 ± 1.5 kg. Rams were randomly divided into three experimental groups: The control group (G1) received standard feed, while ginger powder (5 g and 7 g/kg body weight [BW] for G2 and G3, respectively) mixed in water was administered to groups G2 and G3 before their standard feed. Results: The control group recorded higher dry matter (DM) intake values (p < 0.05) than the ginger-treated groups. The ginger-treated groups showed superiority (p < 0.05) in weight gain and feed conversion compared to the control group. The digestion coefficients of DM, crude protein, and crude fiber were significantly (p < 0.05) increased by a high dose (7 g/Kg BW) of ginger supplementation, whereas organic matter, ether extract, and nitrogen-free extract digestibility remained unchanged. Compared to the control group, the rams given 5 g of ginger had significantly less (p < 0.05) total protein and globulin in their serum, but the rams given 7 g of ginger had significantly more (p < 0.05) of these proteins. In the ginger groups, these levels were significantly (p < 0.01) lower than those in the control group for serum creatinine, uric acid, urea, total lipids, triglycerides, total cholesterol, glucose, serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase. Rams given ginger had significant growth hormone, insulin-like growth factor-1, total superoxide dismutase, GSH-Px, TAC, immunoglobulin (Ig) A, and IgG enhancement (p < 0.01), and a decrease (p < 0.01) in malondialdehyde concentration compared to the control group. Significant increases in total short-chain volatile fatty acids, acetic, propionic, and isovaleric acids (p < 0.05), and significant decreases in NH3N and protozoa (p < 0.01). Conclusion: Ginger powder (5 g and 7 g) can improve growth, immune responses, antioxidant status, and ruminal parameters in rams. Further study is needed to evaluate the effect of ginger on different types of animals (cow, buffalo, and goat) to develop new feed additives.

Effects of fermented jujube powder on growth performance, rumen fermentation, and antioxidant properties of simmental bulls.

Introduction: Fermented jujube powder (FJP) promotes a balance between the intestinal microflora and immune factors in animals. In this study, we aimed to investigate the effects of FJP on the production performance, nutrient digestion, rumen fermentation, and antioxidant properties of bulls. Methods: Forty Simmental bulls were randomly divided into four groups based on body weight and fed a basal diet with [5, 7.5, or 10% dry matter (DM)] or without FJP. The experimental period was 20 d for adaptation and 60 d for the feeding trial. Results: Dietary FJP supplementation did not affect DM intake (P > 0.05) but increased the average daily gain quadratically (P = 0.049) and decreased the feed conversion ratio linearly (P = 0.042). FJP quadratically enhanced DM and crude protein digestibility (P = 0.026 and P = 0.041, respectively) and linearly enhanced acid detergent fiber digestibility (P = 0.048). It also increased the total volatile fatty acid concentration quadratically (P = 0.037), acetate molar percentage, and acetate-to-propionate ratio linearly (P = 0.002 and 0.001), and reduced the ammonia nitrogen concentration linearly (P = 0.003). Additionally, xylanase and protease activities and Ruminococcus flavefaciens abundance increased linearly (P = 0.006, 0.018, and 0.009, respectively), and total bacteria, Ruminococcus albus, and Ruminobacter amylophilus abundance increased quadratically (P = 0.047, 0.011, and 0.021, respectively). FJP linearly increased serum total protein concentration and antioxidant capacity (P = 0.003 and 0.018, respectively) and decreased malonaldehyde content (P = 0.006). Discussion: FJP supplementation (7.5%) enhanced production performance, nutrient digestion, rumen fermentation, and serum antioxidant capacity in bulls. The improved nutrient digestion may be due to an increase in ruminal microorganisms and total volatile fatty acids from the FJP. High blood antioxidant levels indicate that FJP may preserve proteins, thereby boosting the production performance of bulls.

High concentrate diets altered the structure and function of rumen microbiome in goats.

This study used metatranscriptomics to investigate the effects of concentrate diet level on rumen microbiome composition and function in goats. A total of 12 healthy 120-day-old Da'er goats were randomly allotted into two treatments: L group (low dietary concentrate level group, concentrate: forage ratio was 25: 75) and H group (high dietary concentrate level group, concentrate: forage ratio was 80: 20). The study included a 10-day pre-feeding period and a 60-day growth experiment. The results showed that compared with the L group, the average daily gain and the slaughter rate in the H group were increased, while the F/G was decreased; the concentration of lactate and ammonia nitrogen, and the proportion of butyrate and valerate in the rumen of the H group were increased, while the proportion of acetate, and the ratio of acetate to propionate were decreased (p < 0.05). Among rumen bacteria, compared with the L group, the H group significantly decreased the relative abundance of Firmicutes and Fibrobacteria at the phylum level, decreased the relative abundance of Bacteroidetes, Fibrobacter, and Sarcina and increased the relative abundance of Clostridium at the genus level, and decreased the relative abundance of Fibrobacter succinogenes, Sarcina sp. DSM 11001, Oscillibacter sp. KLE 1728, and Ruminococcus flavefaciens and increased the relative abundance of Clostridium sp. ND2 and Firmicutes bacteria CAG: 103 at the species level (p < 0.05). Among rumen fungi, the relative abundance of Basidiomycota, Neocallimastigomycota, Mortierella, Mortierella elongata, and Gonapodyna prolifera was lower in the H group than that in the L group (p < 0.05). Functional annotation results showed that the abundance of Glycoside hydrolases genes in rumen microbiome was significantly decreased in the H group compared to the L group (p < 0.05). The result of KEGG DEGs enrichment analysis showed that the gene expression of cellulose 1,4-ß-cellobiosidase, acetyl-CoA hydrolase, lactate dehydrogenase, succinate-semialdehyde dehydrogenase, D-malate dehydrogenase and related genes in methane production pathways of rumen microbiome was decreased in the H group. In summary, feeding high concentrate diets improved the production performance of goats, altered the structure and composition of rumen microbiome and changed the function of rumen microbiome.

Analysis of the relationship between energy balance and properties of rumen fermentation of primiparous dairy cows during the perinatal period.

Short-chain fatty acids (SCFAs) produced in the rumen are key factors affecting dairy cows' energy balance (EB). This study aimed to quantitatively evaluate the effects of SCFAs production on EB in dairy cows. Primiparous dairy cows were divided into high non-esterified fatty acid (NEFA; group H) and low NEFA (group L) groups based on their blood NEFA levels at week 3 postpartum, which served as an indicator of EB. The amounts of SCFAs produced in the rumen, including acetate, propionate, and butyrate (SCFAsP), were calculated using the predicted rumen volume. Because there were no differences between the groups in SCFAsP/dry matter intake, whereas 4% fat-corrected milk (FCM)/SCFAsP was significantly higher in group H, it was suggested that more body fat was mobilized for milk production in group H. However, group L, which showed better EB, had propionate dominant and lower FCM/SCFAsP and milk energy/SCFAs energy at 3 and 7 weeks postpartum, indicating that group L had a better energy supply for milk production. These results suggest that SCFAsP produced by rumen fermentation and the composition of SCFAs in the rumen affect milk production and EB.

Effect of Replacing Alfalfa Hay with Common Vetch Hay in Sheep Diets on Growth Performance, Rumen Fermentation and Rumen Microbiota.

The aim of this study was to determine whether the inclusion of 40% of common vetch (CV) hay as a feed ingredient in place of alfalfa hay (AH) would improve performance and ruminal fermentation and microbiota in fattening lambs. Twenty lambs were equally divided into two groups: control group (fed 40% AH with 20% rice straw) and CV group (fed 40% CV hay with 20% rice straw). Concerning hay quality, CV hay had greater in vitro digestibility of dry matter and neutral detergent fiber (p < 0.05) than AH. Lambs fed the CV diet had a higher average daily gain (ADG) and efficiency of feed and economy than lambs fed the control group. The NH3-N content and estimated methane produced per unit of ADG of the CV diet group were significantly lower (p < 0.05) than control group. Multiple differential microbial genera were identified, with Prevotella being the most dominant genus and a tendency towards higher (p = 0.095) in lambs offered CV diet. The higher Ruminococcus abundance (p < 0.05) was found in animals of the CV group compared to the control group. In summary, CV can be incorporated into lamb diets as a low-cost forage alternative to AH to improve feed efficiency and animal performance and to reduce methane produced per unit of ADG.

Effects of yeast culture supplementation on milk yield, rumen fermentation, metabolism, and bacterial composition in dairy goats.

The effects of yeast culture (YC) on dairy goat milk yield and potential effects of rumen microbial population changes on rumen fermentation are poorly understood. This study aimed to evaluate the effects of YC on milk yield and rumen fermentation in dairy goats and explore the potential microbial mechanisms. Forty Laoshan dairy goats with a weight of 51.23 ± 2.23 kg and daily milk yield of 1.41 ± 0.26 kg were randomly divided into 4 groups: control (no YC), YC1 (10 g/day per goat), YC2 (25 g/day per goat), and YC3 (40 g/day per goat). The pre-feeding period was 15 days, and the official period was 60 days. Laoshan dairy goats were milked twice daily, and the individual milk yield was recorded. On the last day of the official period, rumen fluid was collected to measure rumen fermentation, perform quantitative polymerase chain reaction (PCR), and detect metabolites. Compared to the control group, the YC group had greater milk yield; higher acetic acid, butyric acid, and total volatile fatty acid contents; and lower ammonia-N (NH3-N) content in the rumen (p < 0.05). YC increased the abundance of Clostridia_UCG-014 and Paraprevotella (p < 0.05). Differential metabolites L-leucine and aspartic acid were screened. This study revealed the microbial mechanisms linking the relative abundance of Paraprevotella and Clostridia_UCG-014 to L-leucine and aspartic acid utilization. These results describe the potential benefits of supplementing 10 g/day per goat YC in the diets of Laoshan dairy goats for improving the rumen environment and milk yield.

Comparative effects of nisin and monensin supplementation on growth performance, rumen fermentation, nutrient digestion, and plasma metabolites of fattening Hu sheep.

Introduction: This study was conducted to compare the effects of nisin (NIS) and ionophore antibiotic monensin (MON) on the growth performance, rumen fermentation, nutrient digestion and plasma metabolites of fattening Hu sheep. Methods: Thirty-six male Hu sheep (23.5 ± 1.0 kg) were divided into two blocks based on BW (low BW and high BW). Sheep within each block were then allotted to 9 pens respectively (two sheep/pen). Pens within each block were randomly assigned to one of three dietary treatments: (1) basal diet (CON); (2) basal diet + 40 mg/kg DM of MON; (3) basal diet + 274.5 mg/kg DM of NIS. The study lasted 9 weeks, with the initial 2 weeks for adaptation and the subsequent 7 weeks for treatment. Results: The results showed that both NIS and MON addition had no impacts on average daily gain (ADG), dry matter intake (DMI), and feed conservation rate (G:F) of sheep (p > 0.05). The digestibility of ether extract (EE) was lower in the MON-fed and NIS-fed sheep (p < 0.01) than in the CON group, whereas crude protein (CP) digestibility was higher in the MON-fed sheep compared to those fed NIS (p < 0.05). Both NIS and MON supplementation decreased acetate levels and acetate/propionate ratio in the rumen of Hu sheep (p < 0.05). Sheep fed MON exhibited higher total cholesterol concentrations (p < 0.05) compared to the CON and NIS groups. However, there were no significant differences in other plasma metabolites, including blood urea nitrogen (BUN), total bile acid, triglyceride, total protein, albumin, globulin, glucose, etc., among the three groups (p > 0.05). Discussion: In conclusion, dietary addition of NIS and MON altered the rumen fermentation mode by reducing acetate levels, with no discernible effects on the growth performance of the fattening Hu sheep.

Effect of replacing concentrates with cassava root-top silage on feed utilization, rumen fermentation, blood parameters and growth performance in beef cattle.

OBJECTIVE: This experiment aimed to evaluate the effects of replacing concentrates with cassava root-top silage (CARTOS) on feed intake, digestibility, rumen fermentation, blood parameters, and growth performance of beef cattle. METHODS: Twenty crossbred bulls with a body weight (BW) of 226±56 kg were randomly assigned to one of five treatments for 90 d in a randomized complete block design having four blocks based on BW. The concentrates were replaced by CARTOS at levels of 0%, 25%, 50%, 75%, and 100% dry matter (DM). Animals were fed dietary treatments at 1.8% BW, with rice straw offered ad libitum. RESULTS: The DM and crude protein (CP) intake were decreased (p<0.01, p = 0.04) when the diet's CARTOS level was increased. The digestibility of DM, OM, and CP were not different among treatments, while fiber digestibility was increased with the inclusion of CARTOS (p = 0.03). The addition of CARTOS to replace concentrates did not change ruminal pH or volatile fatty acid proportions except for acetic acid, which increased with the addition of CARTOS (p = 0.03). The ruminal ammonia-nitrogen (NH3-N) was decreased (p<0.01) with increasing levels of CARTOS. The blood glucose and blood urea nitrogen decreased (p = 0.01) with the addition of CARTOS at 100%, whereas total protein and hematological parameters did not change with increasing levels of CARTOS. The use of CARTOS to substitute concentrates at 75% and 100% decreased average daily gain (ADG) and gain to feed ratio (G:F) (p<0.01); therefore, the addition of CARTOS up to 50% maintained ADG and G:F in beef cattle. CONCLUSION: CARTOS can replace concentrates up to 50% in beef cattle diets without adversely affecting feed intake, nutrient digestibility, rumen fermentation characteristics, blood parameters, or growth performance of beef cattle.