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PubMed2006

Binding of Fusarium mycotoxins by fermentative bacteria in vitro.

AIMS: Fusarium toxins can occur in conserved forages impairing farm animal performances and health. On-farm biological decontamination methods could be an alternative to traditional physico-chemical methods. In this work, the ability to remove Fusarium toxins by fermentative bacteria was evaluated in vitro. METHODS AND RESULTS: Twenty-nine strains of lactic (LAB) and propionic acid bacteria (PAB) were tested for their ability to remove deoxynivalenol (DON) and fumonisins B1 and B2 (FB1, FB2) from an acid, pH 4, medium. Mycotoxin removal was widespread for LAB, but differences among strains were large. Removal was up to 55% for DON, 82% for FB1 and 100% for FB2. Selected strains were also capable of removing up to 88% zearalenone. The PAB strains were less efficient than the LAB. Binding, not biodegradation appeared to be the mode of action, as no toxin derivatives were observed and removal was not impaired in nonviable bacteria. Binding was not affected by pH, except for fumonisins that decreased to nearly 0% at neutral pH. CONCLUSIONS: Selected fermentative bacteria are able to bind main Fusarium mycotoxins. SIGNIFICANCE AND IMPACT OF THE STUDY: The binding ability of selected strains could be used to decrease the bioavailability of toxins in contaminated silages.

Culture Media↗
PubMed1996

Fecal short-chain fatty acids in patients with diarrhea-predominant irritable bowel syndrome: in vitro studies of carbohydrate fermentation.

Colonic bacterial production of short-chain fatty acids (SCFA) plays an important role in the salvage of unabsorbed carbohydrate and in colonic absorption of electrolytes and water. The objective of this study was to determine whether patients with diarrhea-predominant irritable bowel syndrome (DP-IBS) have a different pattern and rate of fermentation of carbohydrate and fiber to SCFA compared with controls. Fecal homogenates from 10 patients with DP-IBS and 10 age-matched controls were studied. SCFA were measured by gas chromatography in baseline fecal samples and in fecal homogenates in an in vitro anaerobic fermentation system after incubation with no additional substrate, lactulose, potato starch, citrus pectin, and hemicellulose over a 24-hour period. Net SCFA production rates were calculated for the first 6 h of the incubation period. Patients with DP-IBS had a consistently different pattern of less total SCFA, a lower percentage of acetate (p < 0.05), and a higher proportion of n-butyrate (p < 0.05) than controls. In stool homogenates from both controls and DP-IBS patients, lactulose fermentation resulted in the highest rate of SCFA production followed by pectin, starch, and hemicellulose. However, at all time points, the fecal homogenates from controls generated a higher concentration of total SCFA, acetate, and propionate with all substrates tested. SCFA production rates were higher in controls incubated with lactulose, starch, and hemicellulose. The fecal SCFA profile of patients with DP-IBS is characterized by lower concentrations of total SCFA, acetate, and propionate and a higher concentration and percentage of n-butyrate. Fecal flora from these patients produced less SCFA in an in vitro fermentation system in response to incubations with various carbohydrates and fibers. Differences in SCFA production by colonic bacterial flora in patients with DP-IBS may be related to the development of gastrointestinal symptoms.

Acetates↗
PubMed2004

Resistant starch derived from processed legumes: in vitro and in vivo fermentation characteristics.

The effect of processing of legumes on resistant starch formation, its rate of fermentation and the production of short chain fatty acids under in vitro and in vivo systems was assessed. The content of resistant starch in pressure-cooked Bengal gram, black gram and red gram was 3.59%, 1.58% and 3.34%, respectively. Fermentation in vitro of resistant starch derived from processed red gram showed higher amount of short chain fatty acids (2.38 mmol), especially butyric acid (2.22 mmol). Under in vivo conditions (in albino rats) all processed legumes showed a higher faecal bulking, and more short chain fatty acids, with a significant increase in the anaerobic bacterial counts. Compared with a processed legume diet, the caecum of animals fed a raw diet showed a preponderance of propionic acid.

Animals↗
PubMed2000

Pretanned leather shavings in a supplement mixture for steers: I. In situ and in vitro disappearance, ruminal fermentation, and organic matter, nitrogen, and fiber digestion.

Two digestion studies were conducted to evaluate the use of pretanned leather shavings as a component of a protein supplement. In Exp. 1, the in situ and in vitro disappearance of pretanned leather shavings and soybean meal was evaluated. Results revealed that less than 18.4% of the pretanned leather shavings was solubilized and disappeared when exposed to McDougall's buffer for 48 h, but there was 90.0% disappearance with 48-h exposure to a .1 N HCl/pepsin treatment and 97.0% disappearance with exposure to a two-stage digestion. In situ disappearance following 72 h in the rumen allowed 6.8% disappearance. Thus, leather shavings seem to be relatively indigestible in the rumen, but postruminal digestion may be possible. In Exp. 2, six Angus x Holstein steers, fitted with ruminal and duodenal cannulas, were used in a replicated 3 x 3 Latin square to evaluate ruminal and digestion effects of the following supplements combined with fescue hay at 1.7% of BW (DM basis): no supplementation (control); supplementation intraruminally with soybean meal at .07% of BW (as-fed basis); and supplementation intraruminally with a combination of soybean meal and pretanned leather shavings (17:8 ratio) at .05% of BW (isonitrogenous to soybean meal; as-fed basis). Ruminal fluid passage rate was greater and fluid turnover time was shorter in steers fed leather shavings than in those fed soybean meal (P = .10). Ruminal pH was lower (P = .04) for supplemented steers than for control steers and ruminal NH3 N concentration was greater (P = .01) in steers fed soybean meal than in those fed leather shavings. Total VFA concentration was increased (P = .02) by supplementation. Supplementation with soybean meal increased (P < .05) ruminal molar proportions of butyrate, valerate, and isovalerate compared with leather shavings. Duodenal OM flow and OM disappearing in the intestines were increased by supplementation (P < .10), but not by the type of supplement fed (P > .10). Ruminal digestion of OM and total tract OM digestion were unaffected (P > .10) by supplementation and the type of supplement fed. Flow and digestion of NDF were unaffected (P > .10) by the treatments. Flow of N and the quantity of N disappearing in the intestines were increased (P < .05) by supplementation but did not differ (P > .10) between supplementation groups. Microbial N flow, N utilization for net microbial protein synthesis, and ruminal N disappearance were unaffected (P > .10) by supplementation and the type of supplement provided. Combining pretanned leather shavings with soybean meal seemed to have no deleterious effects on digestion or fermentation and to allow for escape of some N to the lower tract.

Animal Feed↗
PubMed2003

Supplementation of barley straw with Sesbania pachycarpa leaves in vitro: effects on fermentation variables and rumen microbial population structure quantified by ribosomal RNA-targeted probes.

Tropical livestock is often maintained on roughage-based diets deficient in N, and therefore requires supplementation with protein-rich substrates to achieve reasonable production levels. The optimum inclusion rate of a potential supplement is usually determined by in vivo feeding trials or by in vitro incubation of the diet components to estimate the feed value of the complete diet. The present work simulates a supplementation experiment in vitro, by incubating a pure roughage (barley straw), a pure supplement (Sesbania pachycarpa leaves) and mixtures of the two, with increasing inclusion levels of the supplement, in a short-term batch incubation system. Fermentation kinetics were followed by the release of fermentation endproducts (gas and short-chain fatty acids). Microbial biomass was estimated using ribosomal (r) RNA as internal marker for bacteria and eukaryotes separately. Cell-wall-degrading subpopulations were quantified by hybridisation with taxon-specific oligonucleotide probes targeting Chytridiomycetes, Fibrobacter spp., Ruminococcus albus and R. flavefaciens. Carboxymethylcellulase (CMCase) was assayed as an indicator for cell-wall-degrading activity. The addition of S. pachycarpa leaves stimulated fermentation in all cases. Gas production, and especially rRNA concentration, showed clear maxima at 40 % S. pachycarpa inclusion, rates that significantly exceeded the values interpolated from the incubations of the pure substrates. Short-chain fatty acid yield changed only slightly, but in the same way. The analysis of the microbial population structure showed that the positive effects were mainly mediated through enhanced growth of Ruminococcus spp. Increasing proportions of S. pachycarpa leaves in the diet led to a drastic decline in the total eukaryotic population. This points to a defaunation, which may also have added to the positive effects. The eukaryotic subpopulation of the rumen fungi were affected to a lesser degree. Although the cell-wall-degrading organisms showed positive responses to the supplementation, the CMCase activity was not affected significantly by the supplementation. The present work shows that it is possible to predict optimum inclusion levels for a new feed supplement in vitro and thus reduce in vivo experiments. It was also demonstrated that true supplementation effects occur particularly for the microbial biomass production, which is the primary source of amino acids for the ruminant animal. The analysis of microbial population structure in context with conventional metabolic measurements adds valuable information to interpret the observed effects on production-related variables.

Animal Nutritional Physiological Phenomena↗
PubMed2006

Use of the in vitro cumulative gas production technique for pigs: an examination of alterations in fermentation products and substrate losses at various time points.

An experiment was conducted to examine changes in VFA and ammonia concentrations at different time points using 4 fermentable carbohydrate-rich feed ingredients as substrates and feces of unweaned piglets as inoculum. Fecal inoculum was collected, pooled, and mixed from 9 specially raised (no creep feed or antibiotics) crossbred piglets at 3 wk of age. Inulin, lactulose, molasses-free sugar beet pulp, and wheat starch were used as substrates and were fermented in vitro for 72 h (3 replicates per substrate). Cumulative gas production was measured as an indicator of the kinetics of fermentation. In addition, 3 bottles of substrate per time point with similar contents (amounts of substrate, inoculum, and media) were incubated but were allowed to release their gas throughout incubation. For these latter bottles, fermentation fluid was sampled at incubation time points including every hour between 1 and 24 h and at 48 h, and fermentation end products (VFA, lactate, and ammonia) and OM disappearance were measured. Dry matter and ash were analyzed from the postfermentative samples. The pH of the contents from these bottles was also recorded. The correlation in time between fermentation end products and cumulative gas produced was determined. The results showed that the prolongation of fermentation to 72 h, especially in the case of fast-fermenting inulin and lactulose, may lead to a different end product profile (P < 0.001) compared with the profile observed at the time at which most of the substrate has disappeared. Therefore, we concluded that the fermentation product profile at the end of in vitro fermentation at a specific time point cannot be used to compare fermentability of carbohydrate sources with different fermentation kinetics in terms of gas production.

Ammonia↗
PubMed1993

Effect of Aspergillus oryzae fermentation extract (Amaferm) on in vitro fiber degradation.

The influence of Aspergillus oryzae fermentation extract (Amaferm) on in vitro fiber degradation was determined by incubating eight ground fibrous feed-stuffs with rumen fluid and buffer inoculum. Amaferm was added at 0, .4, .8, or 1.2 g/L of fermentation mixture. Both NDF and ADF degradabilities were determined after 96 h of incubation. Addition of extract had no effect on NDF or ADF degradability of pure cellulose, low endophyte fescue, wheat straw, corn silage, or prairie hay. Addition of Amaferm at .8 or 1.2 g/L increased NDF and ADF degradations of bromegrass hay and alfalfa hay; its addition at .4 or .8 g/L, but not at 1.2 g/L, increased NDF and ADF degradation of high endophyte fescue hay. In a second set of in vitro fermentations, selective antimicrobials (penicillin, streptomycin, and cycloheximide) were used to assess the influence of Amaferm on various microbial groups. The enhanced fiber degradation by Amaferm was attributed to its stimulation of bacterial activity because its addition to whole rumen fluid without or with cycloheximide increased fiber digestion. In contrast, addition of Amaferm to the whole rumen fluid plus penicillin and streptomycin treatment had no effect on fiber degradation, suggesting that fungal or protozoal activity was not affected by treatment. In conclusion, Amaferm increased fiber digestibility of certain feedstuffs, and the increase was mediated via stimulation of rumen bacterial, but not fungal or protozoal, activities.

Animal Feed↗
PubMed2006

Plant extracts affect in vitro rumen microbial fermentation.

Different doses of 12 plant extracts and 6 secondary plant metabolites were incubated for 24 h in diluted ruminal fluid with a 50:50 forage:concentrate diet. Treatments were: control (no additive), plant extracts (anise oil, cade oil, capsicum oil, cinnamon oil, clove bud oil, dill oil, fenugreek, garlic oil, ginger oil, oregano oil, tea tree oil, and yucca), and secondary plant metabolites (anethol, benzyl salicylate, carvacrol, carvone, cinnamaldehyde, and eugenol). Each treatment was supplied at 3, 30, 300, and 3,000 mg/L of culture fluid. At 3,000 mg/L, most treatments decreased total volatile fatty acid concentration, but cade oil, capsicum oil, dill oil, fenugreek, ginger oil, and yucca had no effect. Different doses of anethol, anise oil, carvone, and tea tree oil decreased the proportion of acetate and propionate, which suggests that these compounds may not be nutritionally beneficial to dairy cattle. Garlic oil (300 and 3,000 mg/L) and benzyl salicylate (300 and 3,000 mg/L) reduced acetate and increased propionate and butyrate proportions, suggesting that methane production was inhibited. At 3,000 mg/L, capsicum oil, carvacrol, carvone, cinnamaldehyde, cinnamon oil, clove bud oil, eugenol, fenugreek, and oregano oil resulted in a 30 to 50% reduction in ammonia N concentration. Careful selection and combination of these extracts may allow the manipulation of rumen microbial fermentation.

Ammonia↗
PubMedDate not supplied

Stimulation of the maturation of dendritic cells in vitro by a fermented mistletoe extract.

BACKGROUND: Dendritic cells (DC) play a key role during the initiation of specific immune responses. In cancer patients, however, an alteration of their function was observed. In our investigation we analysed the influence of a fermented mistletoe extract often used for adjuvant treatment of cancer patients on the generation and maturation of DC. MATERIALS AND METHODS: Monocytes from healthy individuals were incubated with a fermented mistletoe extract in the presence or absence of GM-CSF/IL-4. Surface marker expression was measured by flow cytometry. RESULTS: While there was no relevant effect on the generation of DC in the absence or presence of GM-CSF/IL-4 in 5-day cultures, the mistletoe extract significantly stimulated the maturation of pre-generated immature DC, as evidenced by a heightened expression of CD83. Like the positive control TNF-alpha, the mistletoe extract significantly activated CD80 and CD86 as well as HLA class I and II molecules on these cells. CONCLUSION: Our data clearly demonstrate an influence of the mistletoe extract on the maturation of DC, but it remains to be elucidated whether the function of DC is also activated and, especially, whether this effect can be observed in tumour patients as well.

ADP-ribosyl Cyclase↗
PubMed2005

Determination of beta-carotene and lutein available from green leafy vegetables by an in vitro digestion and colonic fermentation method.

Green leafy vegetables (Spinacea oleracea, Cnidoscolus aconitifolius, and Solanum americanum) contain a high amount of beta-carotene (27-52 mg/100 g of dry sample) and lutein (140-193 mg/100 g of dry sample). The amount of beta-carotene and lutein released from the food matrix by the action of digestive enzymes ranged from 22 to 67% and from 27 to 77%, respectively. There was a significant correlation between the enzymatic release of carotenoids (lutein + beta-carotene) and the content of Klason lignin, nonstarch polysaccharides, and resistant protein. The carotenoids released by the in vitro colonic fermentation ranged from 2 to 11%, and part of them (0.251-4.03 mg/100 g of original dry sample) remained intact in the fermentation media and could be potentially absorbed in the colon. A significant part of carotenoids seems to be unavailable in the intestinal tract (16% in S. oleracea to 58% in C. aconitifolius).

Biological Availability↗
PubMed1990

Fermentation of pearl millet flour with yeasts and lactobacilli: in vitro digestibility and utilisation of fermented flour for weaning mixtures.

Single as well as mixed culture fermentation by yeasts (S. diastaticus; S. cerevistiae) and lactobacilli (L. brevis; L. fermentum) at 30 degrees C for 72 h improved the starch and protein digestibility (in vitro) of pearl millet flour significantly. The flour fermented by Saccharomyces diastaticus, a starch hydrolysing yeast, had the highest starch digestibility whereas fermentation by Saccharomyces cerevisiae enhanced the in vitro protein digestibility of the flour significantly. Weaning mixtures prepared from the fermented flour were also found to be organoleptically acceptable.

Dietary Carbohydrates↗
PubMed1976

Effects of fermentation time on in vivo/in vitro relationships.

The effects of six fermentation times, 24 through 84 h at 12 h intervals, were studied on in vivo/in vitro relationships and repeatability and variability of in vitro technique. Three stages of maturity each of bermudagrass, bahiagrass, rye-grass, sorghum-sudan, alfalfa, and orchardgrass were used. For one fermentation time for all types of forages, a 48-h fermentation demonstrated the smallest variation among runs and the least run X forage interaction. However, the optimum fermentation for perennials as a group was 60 h; and for annuals, legumes, and temperate grasses it was 36 h. Further studies in vitro compared a 48-h fermentation for all types of forage with 36 h for annuals and 60 h for perennials. Forty-eight forages, including 20 annuals and 28 perennials, were digested in vitro during three runs. With the 48-h fermentation, forages accounted for 86.43% of the total variation, runs 6.80%, and run X forage interaction 6.44%. Variation due to runs was reduced to .33%, and run X forage interaction to .90%, for a combined 36- and 60-h fermentation for annuals and perennials, respectively. Variation due to forage was increased to 98.53%.

Animal Feed↗
PubMed2001

In vitro mixed ruminal microorganism fermentation of whole cottonseed coated with gelatinized corn starch and urea.

We conducted an in vitro mixed ruminal microorganism fermentation study to determine the effect of coating whole cottonseed with gelatinized corn starch and feed grade urea. Treatments were arranged as a 3 x 4 factorial to provide three concentrations of starch (0.0, 2.5, and 5.0%) and four concentrations of urea (0.0, 0.25, 0.5, and 1.0%). All treatments were prepared from one lot of whole cottonseed. Batch culture fermentations were conducted using anaerobic medium that contained 20% (vol/vol) ruminal fluid in 160-ml serum bottles. Whole cottonseed was ground to pass through a 6-mm screen and weighed amounts (0, 0.4, 0.8, and 1.2 g) were added to the serum bottles. As starch increased, H2, CH4, total volatile fatty acids, and molar proportions of propionate increased linearly, whereas pH, molar proportions of acetate, and the acetate to propionate ratio decreased linearly. L-Lactate concentrations were highest with 2.5% starch compared with 0 or 5.0%. As the amount of urea in the coating increased, pH and CH4 increased linearly, whereas H2 concentrations decreased linearly. Ammonia concentrations exhibited a quadratic response due to moderate increases with the addition of 0.25 and 0.5% urea, and a greater increase was observed with 1.0% urea. Interactions between starch and urea were observed for H2, CH4, NH3, and L-lactate. Concentrations of H2 decreased and CH4 was relatively constant as urea increased in the presence of 0 and 2.5% starch, but increased with 5% starch. L-Lactate concentrations were unchanged (0% starch), higher (2.5% starch), or lower (5.0% starch) as urea increased. Ammonia concentrations increased after urea exceeded 10% of the starch concentration. The addition of urea did not prevent the decline in pH, but did reduce H2 and CH4 accumulation with 2.5% starch.

Animals↗
PubMed1984

Relation of feedlot performance and certain physiological responses to the metabolizable protein and urea content of cattle diets.

An experiment was conducted to test the accuracy of the metabolizable protein system in predicting the amount of urea that would be useful in a corn-based cattle diet. Treatment diets included a basal, low-protein (7.8% CP) negative control (NC) with no supplemental N and a positive control (PC) that contained soybean meal. Urea was added to the NC diet in quantities calculated to be either 25% deficient (LU), equal to (MU) or 25% in excess (HU) of the urea fermentation potential ( UFP ). In vitro rumen fermentation studies were used to determine sequential ammonia production and digestible dry matter content of the diets. In a growth trial, 12 individually-fed Angus, Hereford and Angus X Hereford steers weighing an average of 213 kg were assigned randomly to each treatment diet. At the conclusion of the 112-d trial, rumen ammonia and jugular blood urea N (BUN) concentrations were determined on two steers from each treatment before feeding and at 1, 2, 3, 4 and 5 h postfeeding. In vitro ammonia concentrations of the NC and PC treatments were lower (P less than .05) than that of urea containing diets. In vivo rumen ammonia concentrations at 1 h postfeeding and BUN levels at 3 h postfeeding were low for both the NC and PC diets compared with urea-containing diets. Both of these values increased with each successive increase of added urea to the NC diet. During the initial 70 d of the growth trial, daily gains were improved (P less than .05) by addition of urea up to the MU level, which fulfilled the calculated UFP .(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonia↗
PubMed1999

Effects of a Saccharomyces cerevisiae culture on in vitro mixed ruminal microorganism fermentation.

Previous research has shown that Saccharomyces cerevisiae culture increases lactate utilization and cellulose digestion by pure cultures of ruminal bacteria. Based on these pure culture results, in vitro mixed ruminal microorganism fermentations were conducted to determine the effects of 0.35 and 0.73 g/L of Sacc. cerevisiae culture on the fermentation of ground corn, maltose, alfalfa hay, bermudagrass hay, and lactate. In addition, experiments were performed to evaluate the effects of Sacc. cerevisiae culture and monensin on the mixed ruminal microorganism fermentation. In the presence of ground corn, both concentrations of Sacc. cerevisiae culture had little effect on final pH or fermentation products, except the 0.35 g/L treatment increased valerate concentration. Saccharomyces cerevisiae culture had little effect on final pH or fermentation products in maltose or lactate fermentations. When alfalfa hay was the substrate, 0.73 g/L of Sacc. cerevisiae culture increased propionate concentration and both treatments decreased the acetate to propionate ratio. In the case of Coastal bermudagrass hay, 0.73 g/L Sacc. cerevisiae culture increased concentrations of acetate, propionate, CH4, butyrate, isovalerate, valerate, and decreased the acetate to propionate ratio, whereas both treatments increased total volatile fatty acid concentrations. Similar to alfalfa hay, in vitro dry matter disappearance of Coastal bermudagrass hay was numerically increased in the presence of Sacc. cerevisiae culture. Monensin altered the fermentation by decreasing concentrations of CH4 and lactate and increasing concentrations of propionate. There was no interaction between Sacc. cerevisiae culture and monensin. In conclusion, the incorporation of Sacc. cerevisiae culture into mixed ruminal microorganism fermentations of ground corn, maltose, or lactate had little effect on final pH and fermentation products. However, in the presence of alfalfa hay or Coastal bermudagrass hay Sacc. cerevisiae culture increased concentrations of several fermentation products and numerically increased in vitro dry matter disappearance of forage fiber.

Acetates↗
PubMed2000

In vitro digestibility of bacillus fermented soya bean.

Bacillus fermented legume products include among others dawadawa and soumbala made from African locust bean, and natto and kinema made from soya bean. Bacillus subtilis is the dominant species involved in the fermentation. During Bacillus fermentation for 48 h of autoclaved soya bean the quantity of soluble and dialyzable matter increased from 22% and 6% up to 65% and 40%, respectively. Protein and carbohydrate degradation during fermentation of soya bean with several Bacillus spp. was investigated and appeared to be substantial during the first 18 h of fermentation resulting in the release of high levels of peptides and oligosaccharides. In vitro digestibility was increased from 29% up to 33-43% after Bacillus fermentation for 48 h. It was shown that Bacillus spp. were able to degrade soya bean macromolecules to a large extent resulting in water-soluble low molecular weight compounds. In vitro digestion of Bacillus fermented soya bean using gastrointestinal enzymes only slightly increased the amount of dialyzable matter, which clearly demonstrated the beneficial effect of Bacillus fermentation on food nutrient availability.

Absorption↗
PubMed2002

Effects of Saccharomyces cerevisiae culture and Saccharomyces cerevisiae live cells on in vitro mixed ruminal microorganism fermentation.

The objective of this study was to examine the effects of a Saccharomyces cerevisiae live cell product and a S. cerevisiae culture product on the in vitro mixed ruminal microorganism fermentation of ground corn, soluble starch, alfalfa hay, and Coastal bermudagrass hay. In the presence of ground corn, neither concentration (0.35 or 0.73 g/L) of S. cerevisiae culture nor live cells had any effect on final pH, H2, CH4, propionate, or butyrate. The S. cerevisiae culture had no effect on acetate, but both concentrations of S. cerevisiae live cells decreased acetate and the acetate:propionate ratio. When soluble starch was the substrate, both concentrations of S. cerevisiae live cells and 0.73 g/L of S. cerevisiae culture decreased the acetate:propionate ratio. Although the treatment effects were not statistically significant, both concentrations of live cells and 0.73 g/L of the culture decreased lactate concentrations compared with the control incubations. When alfalfa hay served as the substrate, neither the S. cerevisiae culture nor the live cells had an effect on propionate, butyrate, or the acetate:propionate ratio. Both concentrations of S. cerevisiae culture decreased the final pH and in vitro dry matter disappearance, and the 0.73 g/L treatment decreased the amount of acetate. However, both treatments of S. cerevisiae live cells increased final pH and decreased acetate and in vitro dry matter disappearance. Neither yeast treatment had much effect on the Coastal bermudagrass hay fermentations. In general, both S. cerevisiae supplements seemed to have similar effects on the mixed ruminal microorganism fermentation.

Acetates↗