Different concentrations of grape seed extract affect in vitro starch fermentation by porcine small and large intestinal inocula

BACKGROUND: Grape seed extract (GSE) phenolics have potential health‐promoting properties, either from compounds present within the extract, or metabolites resulting from gastrointestinal tract (GIT) fermentation of these compounds. This study describes how GSE affected the kinetics and end‐products of starch fermentation in vitro using pig intestinal and fecal inocula. Six GSE concentrations (0, 60, 125, 250, 500, and 750 µg ml^?1 were fermented in vitro by porcine ileal and fecal microbiota using starch as the energy source. Cumulative gas production, and end‐point short chain fatty acids and ammonia were measured. RESULTS: GSE phenolics altered the pattern (gas kinetics, and end‐products such as SCFA and NH ) of starch fermentation by both inocula, at concentrations above 250 µg ml^?1. Below this level, neither inoculum showed any significant (P > 0.05) effect of the GSE. CONCLUSION: The results show that GSE phenolics at a concentration over 250 µg ml^?1 can have measurable effects on microbial activity in an in vitro fermentation system, as evidenced by the changes in kinetics and end‐products from starch fermentation. This suggests that fermentation patterns could be conceivably shifted in the actual GIT, though further evidence will be required from in vivo studies. Copyright © 2012 Society of Chemical Industry     

Ruminal degradation of mountain pastures infested by Euphorbia polygalifolia in cattle and sheep: effect of previous grazing in invaded areas

Six cows and eight ewes were distributed in four paddocks according to a factorial design, 2 species (cattle vs sheep) × 2 grazing managements (grazing in pastures invaded vs non‐invaded by Euphorbia polygalifolia), to study the ability of sheep and cattle to ruminally degrade mountain pastures containing E. polygalifolia, as well as the influence of previous grazing in invaded areas. After a period of 17 days, rumen fluids were collected and used as microbial inoculum to examine in vitro fermentation rates and ruminal parameters of infested and non‐infested pastures. Results on parameters of gas production, extent of degradation, ammonia concentration and volatile fatty acid production of infested pastures indicate a better fermentation of this substrate in sheep than in cattle. The absence of noticeable differences when the pasture without this species of spurge was incubated suggests that most variation between ruminant species can be attributed to the presence of E. polygalifolia. The positive effect of previous grazing in invaded areas on rates of gas production, extent of degradation and ammonia concentration supports the hypothesis that the ability to degrade infested pastures may be enhanced by previous consumption, probably through an adaptation of the rumen microbiota. Copyright © 2006 Society of Chemical Industry     

Cell surface properties of <Emphasis Type="Italic">Lactobacillus salivarius</Emphasis> under osmotic stress

The modifications of cell morphology and surface properties of Lactobacillus salivarius under osmotic stress were investigated. When deMan–Rogosa–Sharpe (MRS) medium was supplemented with NaCl (0.8 mol l⁻¹), changes in cell size and shape of L. salivarius cells occurred. A higher autoaggregation percentage and a lower hydrophobicity of L. salivarius determined by microbial adhesion to hydrocarbons were observed under osmotic stress. Moreover, coaggregation was strain specific and depended on incubation time as well as growth medium. On the other hand, fatty acid analysis by gas chromatograph–mass spectrometer revealed increases in the ratio of saturated/unsaturated fatty acids and cyclopropaneoctanoic acid, which is a useful way to enhance their osmotic resistance for maintaining the structural and functional integrity of cell membranes.     

Effect of fibrolytic enzymes and an inoculant on in vitro degradability and gas production of low‐dry matter alfalfa silage

BACKGROUND: The objective of this study was to investigate the effect of polysaccharide‐degrading enzymes (a cellulase and a xylanase) alone or in a combination with a bacterial inoculant on fermentation parameters and in vitro degradability and gas production of low‐dry matter (DM) alfalfa silage. First cut alfalfa (Medicago sativa L.), harvested at about 5% bloom stage [260 g kg^?1 dry matter (DM)] was ensiled in laboratory‐scale silos without preservatives or preserved with formic acid, a cellulase (Cell), a xylanase, a cellulose/xylanase enzyme combination (Cell/Xyl), a lactic acid bacteria‐based inoculant (Inoc), and a mix of Inoc and Cell (Inoc/Cell). Triplicate silos were opened on days 1, 3, 7, 15 and 60. RESULTS: Silage pH and ammonia N and total free amino acids concentrations were the lowest (P < 0.05) for the formic acid silage. Inoc and Inoc/Cell produced the highest (P < 0.05) lactate concentration in the 60‐day silage. In vitro degradability of silage DM was not affected (P = 0.998) by treatment, but amylase‐treated neutral detergent fiber degradability was increased (P < 0.05) by formic acid. Compared with the control (51.3 mL 100 mg^?1 silage DM), all treatments except Cell/Xyl increased (P < 0.001) the 24 h cumulative gas production. CONCLUSIONS: Overall, enzyme and lactic acid bacteria‐based preparations had minor effects on silage fermentation in this experiment. The increased cumulative gas production indicates some preservation or liberation of fermentable organic matter with most treatments tested. It is not clear, however, to what extent this effect would impact silage ruminal degradability in vivo. Copyright © 2008 Society of Chemical Industry     

Effect of substrate adaptation on the microbial fermentation and microbial composition of faecal microbiota of weaning piglets studied in vitro

The in vitro cumulative gas production technique can be used to assess microbial activity of a complex community, in relation to fermentation of a particular energy source. Therefore, in combination with an in vivo study to examine the effects of two different diets for weaning piglets, microbial activities of faeces were compared from animals on the two different diets. The two diets were: CHO diet [containing added fermentable carbohydrates, including sugarbeet pulp (SBP) and wheat starch (WST)], and control diet without any added fermentable carbohydrates. Neither diet contained antibiotics or extra added copper. Twenty‐four piglets were selected from 12 litters (two per litter), weaned at 4 weeks of age (neither creep feeding nor any antibiotic treatment before and during the study), and introduced to one of the two diets. After 9 days on the diet, faecal samples were collected from selected animals, and tested for their activity in terms of gas production kinetics, and end‐products such as volatile fatty acids, ammonia and dry matter disappearance of the two test substrates SBP and WST. The bacterial diversity was also analysed before and after in vitro fermentation using denaturing gradient gel electrophoresis analysis of amplified 16S rRNA genes. There were differences both in kinetics and end‐products of the substrates. More interestingly, significant differences were detected between inocula, although mainly in terms of fermentation kinetics of the two substrates. With the CHO inoculum, SBP was fermented faster than with the control, while this effect was reversed for WST. Significantly higher diversity, as measured by DGGE fingerprint analysis, was detected in the microbial community enrichment on SBP as compared with WST at the end of fermentation. The difference between the kinetics of SBP compared with WST fermentation by faecal microbiota from the CHO diet fed piglets suggests better adaptation to SBP fermentation than to WST fermentation. The WST fermentation was more unexpected, given that a significant amount of starch is known to be fermentable by the small intestinal microbiota. It was concluded that the microbial community composition and activity in the GIT may be changed in response to diet, and that this change can be detected in vitro. Copyright © 2005 Society of Chemical Industry     

Ammonia concentration and protein synthesis in the rumen

The effect of rumen ammonia concentration on microbial protein synthesis and fermentation was studied in three separate experiments. In each experiment three separate sheep were fed semi-purified diets [designated A (‘concentrate’), B (‘roughageconcentrate’) or C (‘roughage’)] and infused intra-ruminally with five graded amounts of urea according to a randomised block design. Rumen ammonia concentrations remained low until the total nitrogen intake was about 10 g day^?1 after which rumen ammonia concentration rose rapidly. Rumen and duodenal ammonia concentrations were linearly related (r=0.90, 0.98 and 0.84 for diets A, B and C, respectively; P< 0.001). Microbial protein production did not increase when rumen ammonia concentrations exceeded 2.8 mM for diet A, 6.0 mM for diet B and 1.6 mM for diet C. Diets A and C produced a propionate-type fermentation while diet B was characterised by an acetate-type fermentation. Rumen ammonia concentration had no apparent effect on either concentration or the molar proportions of volatile fatty acids. There were no systematic trends in digestibility in relation to rumen ammonia concentration.     

In vitro fermentation characteristics of diets with different forage/concentrate ratios: comparison of rumen and faecal inocula

BACKGROUND: The aim of this trial was to evaluate the replacement of rumen fluid with faeces as inoculum in studying the in vitro fermentation characteristics of diets for ruminants using the in vitro gas production technique. Six iso‐protein diets with different forage/concentrate ratios were incubated with rumen fluid (RI) or faeces (FI) collected from sheep. RESULTS: Most of the fermentation parameters were influenced by diet and inoculum (P < 0.01). With both inocula, organic matter degradability (dOM), cumulative gas production (OMCV) and maximum fermentation rate (R_max) increased as the amount of concentrate in the diet increased. R_max was lower with FI vs RI (P < 0.01); dOM was higher with FI vs RI and the diet × inoculum interaction was significant. As expected, with both inocula, R_max increased as the neutral detergent fibre content of the diet decreased. Significant correlations were obtained using both inocula between OMCV/dOM and gas/volatile fatty acid (VFA), while the correlation VFA/dOM was significant only with FI. The microbial biomass yield calculated by stoichiometric analysis for all diets was higher with FI vs RI. With FI the organic matter used for microbial growth showed an overall decreasing trend as the amount of concentrate in the diet increased. CONCLUSION: The results indicate that both faeces and rumen fluid from sheep have the potential to be used as inoculum for the in vitro gas production technique. Copyright © 2011 Society of Chemical Industry     

Fermentation, degradation and microbial nitrogen partitioning for three forage colour phenotypes within anthocyanidin-accumulating Lc-alfalfa progeny

BACKGROUND: Alfalfa has the disadvantage of having a rapid initial rate of protein degradation, which results in pasture bloat, low efficiency of protein utilisation and excessive nitrogen (N) pollution into the environment for cattle. Introducing a gene that stimulates the accumulation of monomeric/polymeric anthocyanidins might reduce the ruminal protein degradation rate (by fixing protein and/or direct interaction with microbes) and additionally reduce methane emission. The objectives of this study were to evaluate in vitro fermentation, degradation and microbial N partitioning of three forage colour phenotypes (green, light purple‐green (LPG) and purple‐green (PG)) within newly developed Lc‐progeny and to compare them with those of parental green non‐transgenic (NT) alfalfa. RESULTS: PG‐Lc accumulated more anthocyanidin compared with Green‐Lc (P < 0.05), with LPG‐Lc intermediate. Volatile fatty acids and potentially degradable dry matter (DM) and N were similar among the four phenotypes. Gas, methane and ammonia accumulation rates were slower for the two purple‐Lc phenotypes compared with NT‐alfalfa (P < 0.05), while Green‐Lc was intermediate. Effective degradable DM and N were lower in the three Lc‐phenotypes (P < 0.05) compared with NT‐alfalfa. Anthocyanidin concentration was negatively correlated (P < 0.05) with gas and methane production rates and effective degradability of DM and N. CONCLUSION: The Lc‐alfalfa phenotypes accumulated anthocyanidin. Fermentation and degradation parameters indicated a reduced rate of fermentation and effective degradability for both purple anthocyanidin‐accumulating Lc‐alfalfa phenotypes compared with NT‐alfalfa. Copyright © 2012 Society of Chemical Industry     

Fermentation characteristics of corn‐, triticale‐, and wheat‐based dried distillers' grains with solubles in barley‐based diets determined using continuous and batch culture systems

BACKGROUND: Dried distillers' grains with solubles (DDGS) are becoming increasingly available and popular as an alternative livestock feed. This study used continuous and batch culture techniques to compare the in vitro fermentation characteristics of diets containing corn‐, triticale‐ or wheat‐based DDGS at 200 g kg^?1 diet dry matter (DM) against a barley grain‐based control diet. RESULTS: In continuous fermentation of wheat DDGS diet, total volatile fatty acid (VFA) concentration was decreased by 15.7% across sampling times and NH₃ concentration was quadrupled compared with control, whereas fermentations of corn‐ and triticale‐DDGS diets were similar to the barley‐based control. In batch cultures, corn DDGS differed from control only in increased culture pH. Compared with control diet, triticale DDGS yielded lower total gas production (140.94 versus 148.78 mL g^?1 DM) and in vitro DM digestibility (IVDMD; 0.509 versus 0.535). Wheat DDGS diet yielded decreased total gas production (123.49 mL g^?1 DM) and IVDMD (0.468), as well as total VFA production (105.84 versus 134.20 mmol L^?1) and substantially increased ammonia concentration (151.61 versus 58.34 mg L^?1) and acetate:propionate ratio (2.94 versus 1.11). CONCLUSION: Corn‐ and triticale‐ DDGS diets exhibited fermentation characteristics similar to the barley based control diet, consistent with in vivo findings that these diets yielded no adverse effects on production. In vitro ruminal fermentation of wheat DDGS diet differed significantly from control in several aspects including 2.6 to 6X higher ammonia concentrations. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd     

Microbial and physicochemical succession in fermented sausages produced with bacteriocinogenic culture of Lactobacillus sakei and semi-purified bacteriocin mesenterocin Y

The influence of the bacteriocinogenic culture Lactobacillus sakei (10⁵/g) and semi-purified bacteriocin mesenterocin Y (2560 AU/kg) on the safety and quality of traditional Croatian fermented sausages was investigated. The addition of Lb. sakei and/or mesenterocin Y reduced microbial counts (P < 0.05) in the final products. After 28 days of ripening, coagulase-negative cocci decreased 1.5–2.0 log, yeasts 1.2–1.4 log and enterococci 1.7–2.7 log. In the case of the addition of Lb. sakei, the lactic acid bacteria count was significantly (P < 0.05) higher at day 7 of ripening, and was accompanied by a lower pH and a higher amount of lactic acid (P < 0.05). In the final product the amount of acetic acid was significantly lower. More intensive proteolysis and an increase in ammonia content were found at the beginning of fermentation, and in the second phase of ripening in the control samples, respectively. The free fatty acid concentration was significantly lower during the entire ripening process compared to the control (P < 0.05). Semi-purified mesenterocin Y did not affect the sensory properties of the sausages, whilst the addition of Lb. sakei enhanced them.     

Effects of tannic acid and quebracho tannins on in vitro ruminal fermentation of wheat and corn grain

Current understanding of the effect of moderate amounts of tannins on the utilization of protein contained in forages indicates beneficial effects when fed to ruminants. Nevertheless, there is little knowledge about the effects of tannins on the ruminal hydrolysis of starch‐rich concentrates. Modulation of the hydrolysis of starch may reduce the occurrence of metabolic disorders, such as acidosis, in ruminants consuming high‐grain diets. The effects of commercial tannic acid (hydrolysable tannins) and quebracho tannins (condensed tannins) (50 g kg^?1 DM) on the in vitro fermentation of ground wheat and corn grains by mixed ruminal bacteria was examined. The architecture and chemical composition of wheat and corn endosperms might explain differences in fermentation rates, as well as in response to similar concentrations of tannins. Regardless of the source of tannin, microbial fermentation was inhibited in both grains, as demonstrated by a decline in gas production, DM disappearance, volatile fatty acids and ammonia production. However, these effects were more pronounced for wheat than corn grain, mostly during the initial stages of the incubation. Scanning electron microscopy revealed that both sources of tannins inhibited the microbial hydrolysis of the endosperm protein matrix. Tannins did not prevent bacterial attachment to starch granules, but starch hydrolysis was slowed indirectly as a result of a tannin‐mediated reduction in the degradation of the surrounding protein matrix. Tannins are likely to be more effective at modulating the rate of starch digestion in grains that possess a readily degradable protein matrix. Copyright © 2006 Society of Chemical Industry     

Effect of humic acid on fermentation and ciliate protozoan population in rumen fluid of sheep in vitro

BACKGROUND: Humic acid (HA) as a product of decomposition of animal and plant tissue is used in animal production as a feed supplement, antimicrobial product and growth stimulator. The objective of the present in vitro study was to investigate the effects of dietary humic acid as a commercial Humacid 60 Basic (H60B) feed additive preparation on rumen fermentation and the ciliate protozoan population in the rumen fluid of sheep using a high fibre (HF) and high concentrate (HC) diet in batch cultures and artificial rumen (RUSITEC). RESULTS: Production of total volatile fatty acids (VFAs) was significantly decreased (P < 0.001) for batch cultures by the HF‐H60B diet. The HF‐H60B diet decreased ammonia N in RUSITEC (P < 0.001). An increase in the population of Enoploplastron triloricatum, Isotricha spp. and Ophryoscolex c. tricoronatus with the HF‐H60B diet and Diploplastron affine with the HC‐H60B was observed. The H60B did not affect the total ciliate population and Entodinium spp. CONCLUSION: It can be concluded that dietary humic acid preparations are not effective as dietary antiprotozoal agents. Humic acid might enhance microbial growth and energy efficiency in doses up to 10 g kg^?1 DM of diet. Copyright © 2009 Society of Chemical Industry     

Use of Laser‐Etched Pouches to Control the Volume Expansion of Kimchi Packages During Distribution: Impact of Packaging and Storage on Quality Characteristics

Use of laser‐etched pouches was investigated to develop kimchi packages with gas control functions. According to the degree of laser processing, the headspace pressure, atmospheric composition, and water vapor transmission rate of the kimchi packages were measured to investigate the potential use of laser‐etched packages for kimchi. In addition, the pH, titratable acidity, organic acid, and microbial population of the packaged kimchi were examined to study the effect of packaging and storage conditions on its quality characteristics. The concentration of carbon dioxide in the pouches with a high gas transmission rate was less than that in other pouches (P < 0.05), indicating that low a carbon dioxide concentration resulted in less volume expansion. During the storage period (P < 0.05), the gas pressure in some pouches started to increase after the 15th d at 10 °C. Few differences were observed between the quality characteristics of kimchi (for example, pH, titratable acidity, organic acid, and microbial count). In addition, this study indicated that the higher the storage temperature, the more rapid the fermentation. Consequently, laser‐etched pouches demonstrate the potential for controlling the gas, which in turn maintains the quality of kimchi. The use of laser‐etched films could exert marked effects on alleviating the volume expansion or pressure build‐up in kimchi packages.     

The effect of casein,urea and dried poultry waste on the fermentation of starch or cellulose measured in vitro

Comparative studies on the effects of casein, urea and poultry waste on the fermentation of starch and cellulose were conducted. Incubation of starch with poultry waste for 390 min resulted in greater overall gas, total VFA and ammonia production than in control incubations (grass cubes and hay). Between 210 and 390 min the ammonia concentration fell, indicating microbial utilisation of nitrogen. Replacement of poultry waste with casein resulted in lower gas and total VFA production and similar ammonia concentrations in comparison with the control incubation. When starch was incubated with urea, the ammonia concentration rose rapidly, causing an elevated pH and poor VFA production. When cellulose was incubated with any of the three nitrogen sources, gas and total VFA production were considerably lower than in control incubations. Inclusion of urea as a nitrogen source had an effect on cellulose fermentation similar to that seen with starch. When grass cubes and hay were incubated with poultry waste, gas production was similar to that of the control; however, ammonia and total VFA production were greater than in the control. The results indicate that the carbohydrate content of poultry waste may be useful in promoting the establishment of fermentation, and that the slow release of ammonia may facilitate a more efficient fermentation of roughage in nutrients such as grass and hay.     

Effects of varying the degree of synchrony of energy and nitrogen release in the rumen on the synthesis of microbial protein in lactating dairy cows consuming a diet of grass silage and a cereal-based concentrate

The object of the experiment was to test the hypothesis that altering the degree of synchrony in the ruminal release of available energy and nitrogen would affect microbial protein synthesis (MPS) when the diet contained a high proportion of readily fermentable carbohydrate. Four lactating dairy cows were given a basal diet of (kg DM day⁻¹) 8.0 grass silage, 4.2 barley and 1.8 groundnut meal containing 31.4 g N kg⁻¹ DM. The experiment was designed as a 4 × 4 Latin square with periods lasting 14 days. The treatments were (1) the basal diet given in two equal meals at 10:00 and 22:00 h (BASAL), supplemented with (2) 2.0 kg maltodextrin given as a continous intraruminal infusion (CONT), (3) 2.0 kg maltodextrin as two 6-h infusions starting at 10:00 and 22:00 h (SYNC) and (4) 2.0 kg maltodextrin given as two 6-h infusions starting at 16:00 and 04:00 h (ASYNC). All three infusion treatments reduced (P < 0.05) the concentration of ruminal ammonia relative to BASAL but only the CONT and SYNC treatments increased (P < 0.05) MPS over the level with BASAL; the value for ASYNC was the same as that for BASAL. Lactic acid was a minor product of the ruminal fermentation with all treatments. All three infusions reduced (P < 0.05) the plasma concentration of urea and the urinary output of nitrogen but there were no differences among the infusion treatments. It is concluded that with this diet, containing about 30% of DM as fermentable carbohydrate, altering the degree of synchrony in the rates of ruminal release of energy and nitrogen had a marked effect on MPS. © 1999 Society of Chemical Industry     

In vitro gas production profiles and fermentation end‐products in processed barley,maize and milo

BACKGROUND: An experiment was carried out to establish whether using a pre‐compacting device (expander) changes the contribution of dry matter (DM) and degradative behaviour of grains of barley, maize and milo pre‐processed by grinding over the different DM fractions (non‐washable (NWF), insoluble washable (ISWF) and soluble washable (SWF) fractions). Samples of the entire concentrate ingredients (WHO ingredients) and their different fractions (NWF, ISWF and SWF) were subjected to three processes (Retsch‐milled (R), expander‐treated (E) and expander‐pelleted (EP) samples) and their fermentation characteristics were evaluated using an in vitro gas production technique. RESULTS: The E process increased the size of the NWF and decreased that of the SWF compared with the R process. The ISWF of R samples was very rich in starch. The maximum fractional rate of substrate degradation and maximum rate of gas production were higher in EP samples than in R samples (P < 0.05). In maize and milo the E and EP processes shifted the pattern of fermentation towards a more glucogenic fermentation, as represented by a lower non‐glucogenic/glucogenic ratio (NGR). In all grains the ammonia concentration (NH₃‐N) and branched chain ratio (BCR) of E and EP samples were significantly (P < 0.05) lower than those of R samples. CONCLUSION: It is concluded that the E and EP processes have the potential to synchronise the fermentation of dietary proteins and carbohydrates and shift the pattern of fermentation towards a more glucogenic fermentation. Copyright © 2009 Society of Chemical Industry     

Comparison of sheep and red deer rumen fluids for assessing nutritive value of ruminant feedstuffs

Four forages (alfalfa hay, barley straw, maize silage and beet pulp), four cereal grains (barley, maize, sorghum and wheat) and four shrubs (Calluna vulgaris, Erica australis, Cytisus cantabricus and Genista occidentalis) were incubated using rumen fluids from sheep and red deer, to examine differences in in vitro fermentation rates and ruminal parameters. For the forages and cereal grains, results suggest few differences between species in parameters related to gas production, rates of fermentation, organic matter disappearance and extent of degradation. Deer showed slightly better results for shrubs than sheep did. Disappearance of neutral detergent fibre was generally greater when the rumen fluid was derived from red deer (P < 0.05). On the other hand, ammonia‐N concentration and total volatile fatty acids (VFAs) were higher in sheep (P < 0.05). Molar proportions of the major VFAs showed significant differences (P < 0.05) associated with the species of the inoculum donor and suggest that fermentation pathways might have been more efficient in red deer. The estimated amount of methane was higher in sheep, regardless of the substrate incubated (P < 0.001). The results indicate that although the sheep could be valid as a model to assess the nutritive value of good quality feedstuffs for red deer, it would fail to offer reliable information on non‐conventional, low‐quality feeds such as shrubs. Copyright © 2005 Society of Chemical Industry     

Effect of applying formic acid,heterolactic bacteria or homolactic and heterolactic bacteria on the fermentation of bi‐crops of peas and wheat

This work aimed to compare the effectiveness of bacterial inoculants or a chemical additive for preserving whole‐crop silages made from wheat, two pea varieties (cv Magnus or Setchey) or intercrops of wheat and both pea varieties. The forages were harvested when the wheat and peas were at the late milk and yellow wrinkled stages respectively, and conserved in five replicate mini silos without treatment (control) or after treatment with 2.5 g kg^?1 of formic acid (FA) or 1 × 10⁶ cfu g^?1 fresh forage of either of two bacterial inoculants (WholeCrop Gold (WCG) or WholeCrop Legume (WCL), Biotal Ltd, Cardiff, UK). WCG contained Lactobacillus buchneri, while WCL contained L buchneri, L plantarum and Pediococcus pentosaceus. Chemical composition, fermentation characteristics and in vitro digestibility were measured after 65 days of ensiling. Additive‐treated bi‐crops had lower (P < 0.05) concentrations of soluble N, ammonia N and lactic acid than the controls. Inoculant‐treated bi‐crops had higher (P < 0.001) acetic acid and lower (P < 0.001) residual water‐soluble carbohydrate (WSC) concentrations than FA‐treated bi‐crops. WCL‐treated bi‐crops had similar residual WSC concentrations to and higher (P < 0.05) starch concentrations than WCG‐treated bi‐crops. Unlike Magnus pea bi‐crops, Setchey pea bi‐crops treated with WCL had lower concentrations of ammonia N (P < 0.01) and acetic acid (P < 0.001) and higher concentrations of starch (P < 0.001) and lactic acid (P < 0.05) than those treated with WCG. For both bi‐crops, FA‐treated bi‐crops were more stable (P < 0.05) than inoculant‐treated or untreated silages, and the stability of inoculant‐treated and untreated silages was similar. Formic acid treatment was also the most effective at reducing WSC losses in the bi‐crop and pea silages. Inoculant treatment reduced proteolysis in these forages but did not prevent spoilage in the bi‐crops. Additive treatment reduced yeast counts but did not improve the fermentation in wheat silages. Copyright © 2004 Society of Chemical Industry     

Effects of cinnamon leaf, oregano and sweet orange essential oils on fermentation and aerobic stability of barley silage

BACKGROUND: Silage additives are marketed with the primary aim of improving the fermentation and/or aerobic stability of silage. The objective of this study was to evaluate the impact of three different essential oils (EOs; cinnamon leaf (CIN), oregano (ORE) and sweet orange (SO)) on the fermentation characteristics and stability of barley silage. Chopped whole‐plant barley (Hordem vulgare L.) forage was ensiled either untreated (0 mg kg^?1 dry matter (DM)) or treated with CIN, ORE or SO (37.5, 75 and 120 mg kg^?1 DM). RESULTS: Moulds were not detected in any treatments, including the control, after 7 days of air exposure. All EOs at a concentration of 120 mg kg^?1 silage DM decreased (P = 0.001) yeast populations in comparison with the control during air exposure. Net gas, methane and ammonia concentrations in vitro did not differ among treatments. Changes in volatile fatty acid concentrations were small, and in situ data showed no changes in DM and neutral detergent fibre digestion rates for CIN, ORE or SO at concentrations up to 120 mg kg^?1 DM. CONCLUSION: The findings from this study show that a concentration of 120 mg EO kg^?1 DM decreased yeast counts during aerobic stability tests. However, all EO treatments had minimal effects on data from in vitro and in situ incubations. Copyright © 2011 Crown in the right of Canada. Published by JohnWiley & Sons, Ltd     

Effects of California chaparral plants on in vitro ruminal fermentation of forage and concentrate diet

BACKGROUND: The combustible nature of chaparral plants has been attributed to the presence of secondary compounds such as phenolic acids, flavonoids and essential oils, among others. However, the implication of the antimicrobial properties of secondary compounds of chaparral in modulating rumen microbial metabolism has not been determined. The effects of 11 chaparral plants on rumen microbial fermentation were assessed in an in vitro batch culture fermentation fed a barley silage:barley grain‐based low concentrate (LC) and high concentrate (HC) diets. RESULTS: With LC, gas production [g dry matter (DM) incubated] and DM disappearance (DMD) were unaffected by Adenostoma fasciculatum, Ceanothus cuneatus, Baccharis pilularis or Eriodictyon californicum, but all plants except C. cuneatus decreased (P < 0.05) CH₄ production. With HC diet, all species except A. fasciculatum decreased (P < 0.01) total gas produced. Total volatile fatty acids (VFA) produced, molar proportions of acetate, propionate and butyrate, and the acetate:propionate (A:P) ratio were unaffected by chaparral addition to both HC and LC diets. Increased concentrations of A. fasciculatum and E. californicum decreased (linear; P < 0.05) fermentability and productions of CH₄ and NH₃‐N. CONCLUSION: Among all chaparral species investigated A. fasciculatum and E. californicum added as 10% of LC diet showed some potential to exert beneficial effects on rumen microbial fermentation. © Her Majesty the Queen in Right of Canada 2012