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Aims: To obtain insights into how bacterial and fungal microbiota and fermentation products composition are affected by storage temperature for TMR silage, which can be manufactured year-round., Methods and Results: TMR silage was stored at 10°C, 25°C, ambient temperature (AT; 20-35°C) and 40°C. Lactic acid production was delayed when stored at 10°C, and acid production stagnated after 2 weeks when stored at 40°C. The patterns of acetic acid and ethanol production were inversely related, with ethanol production promoted at 10°C and 25°C and acetic acid production promoted at AT and 40°C. The bacterial diversity was reduced in TMR silage with high lactic acid and acetic acid content, and the fungal diversity was reduced in TMR silage with high ethanol content., Conclusions: The intensity of lactic acid production was accounted for by the high abundance of Lactobacillus, and its stagnated production at a substantially high storage temperature was related to an increased abundance of Bacillus. The enhanced production of acetic acid or ethanol can be explained by differences in the fungal microbiota., Significance and Impact of the Study: The integrated analysis of bacterial and fungal microbiota can provide in-depth insights into the impact of storage temperature on TMR silage fermentation., (© 2022 Society for Applied Microbiology.)

In order to assess the survival of lactic acid bacteria (LAB) in whole crop maize silage in the gut of dairy cows, one representative silage sample and three different feces samples were collected from dairy cows on three dairy farms in Hua Bei, China and three dairy farms in Kyushu, Japan. The composition of the bacterial community was examined by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction. Lactobacillus acetotolerans was detected in all bunker-made maize silage samples, regardless of the dairy farm or sampling region from which they were sourced. A total of eight LAB species were detected in the maize silage samples, of which three (L. acetotolerans, L. pontis and L. casei) appeared to survive digestion. The populations of L. acetotolerans in silage and feces were 10 6-7 and 10 3-4 copies/g, respectively, indicating that, even for the LAB species showing potential survival in the gut, competition in this niche may be harsh and the population may substantially decrease during the digestion process. It may be difficult for silage LAB to survive in the gut of silage-fed dairy cows, because marked decrease in population can take place during the digestion process, even for surviving species., (© 2017 Japanese Society of Animal Science.)

The microbiota of whole crop corn silage and feces of silage-fed dairy cows were examined. A total of 18 dairy cow feces were collected from six farms in Japan and China, and high-throughput Illumina sequencing of the V4 hypervariable region of 16S rRNA genes was performed. Lactobacillaceae were dominant in all silages, followed by Acetobacteraceae, Bacillaceae, and Enterobacteriaceae. In feces, the predominant families were Ruminococcaceae, Bacteroidaceae, Clostridiaceae, Lachnospiraceae, Rikenellaceae, and Paraprevotellaceae. Therefore, Lactobacillaceae of corn silage appeared to be eliminated in the gastrointestinal tract. Although fecal microbiota composition was similar in most samples, relative abundances of several families, such as Ruminococcaceae, Christensenellaceae, Turicibacteraceae, and Succinivibrionaceae, varied between farms and countries. In addition to the geographical location, differences in feeding management between total mixed ration feeding and separate feeding appeared to be involved in the variations. Moreover, a cow-to-cow variation for concentrate-associated families was demonstrated at the same farm; two cows showed high abundance of Succinivibrionaceae and Prevotellaceae, whereas another had a high abundance of Porphyromonadaceae. There was a negative correlation between forage-associated Ruminococcaceae and concentrate-associated Succinivibrionaceae and Prevotellaceae in 18 feces samples. Succinivibrionaceae, Prevotellaceae, p-2534-18B5, and Spirochaetaceae were regarded as highly variable taxa in this study. These findings help to improve our understanding of variation and similarity of the fecal microbiota of dairy cows with regard to individuals, farms, and countries. Microbiota of naturally fermented corn silage had no influence on the fecal microbiota of dairy cows.

The microbiota of pre-ensiled crop and silage were examined using denaturing gradient gel electrophoresis (DGGE) and next-generation sequencing (NGS). Wilted Italian ryegrass (IR), whole crop corn (WC), and wilted alfalfa (AL) silages stored for 2 months were examined. All silages contained lactic acid as a predominant fermentation product. Across the three crop species, DGGE detected 36 and 28 bands, and NGS identified 253 and 259 genera in the pre-ensiled crops and silages, respectively. The NGS demonstrated that, although lactic acid bacteria (LAB) became prevalent in all silages after 2 months of storage, the major groups were different between crops: Leuconostoc spp. and Pediococcus spp. for IR silage, Lactobacillus spp. for WC silage, and Enterococcus spp. for AL silage. The predominant silage LAB genera were also detected by DGGE, but the presence of diverse non-LAB species in pre-ensiled crops was far better detected by NGS. Likewise, good survival of Agrobacterium spp., Methylobacterium spp., and Sphingomonas spp. in IR and AL silages was demonstrated by NGS. The diversity of the microbiota described by principal coordinate analysis was similar between DGGE and NGS. Our finding that analysis of pre-ensiled crop microbiota did not help predict silage microbiota was true for both DGGE and NGS.

Aim: To gain insights into the bacterial species associated with anaerobic storage and aerobic stability of alfalfa silage., Methods and Results: Wilted alfalfa silage (498 g dry matter kg(-1) ) was prepared with and without the addition of molasses. Aerobic spoilage tests were conducted at 5, 10 and 60 days after ensiling. The composition of fermentation products and the bacterial communities of silage were determined at 1, 3, 5 and 7 days after silo opening. Silage without molasses had small amounts of lactic and acetic acids detectable at silo opening but resisted deterioration due to aerobic spoilage for at least 5 days after opening. Resistance to aerobic deterioration in silage increased with the addition of molasses. The predominant bacterial species in molasses-added silage was Lactobacillus fructivorans, which was detected by denaturing gradient gel electrophoresis analysis. Different bacterial growth media were used for Lact. fructivorans isolation from alfalfa silage with added molasses: isolation was successful using liver infusion sake medium, but was unsuccessful when de Man, Rogosa and Sharpe medium was used., Conclusion: A nonconventional lactic acid bacterium (LAB) species may be involved in the high aerobic stability of alfalfa silage., Significance and Impact of the Study: The findings demonstrate that culture-independent microbiota analysis may be useful in the isolation and identification of nonconventional LAB species involved in fermentation and the aerobic stability of silage., (© 2015 The Society for Applied Microbiology.)

To study the microbial population and fermentation dynamics of large needlegrass (LN) and Chinese leymus (CL) during ensiling and subsequent exposure to air, silages were sampled and analyzed using culture-based techniques and denaturing gradient gel electrophoresis (DGGE). A total of 112 lactic acid bacteria (LAB) strains were isolated and identified using the 16S rRNA sequencing method. Lactic acid was not detected in the first 20 days in LN silage and the pH decreased to 6.13 after 45 days of ensiling. The temperature of the LN silage increased after approximately 30 h of air exposure and the CL silage showed a slight temperature variation. Enterococcus spp. were mainly present in LN silage. The proportion of Lactobacillus brevis in CL silage increased after exposure to air. LN silage with a higher proportion of Enterococcus spp. and propionic acid concentration did not show higher fermentation quality or aerobic stability than CL silage, which had a higher concentration of acetic acid, butyric acid and increased proportion of L. brevis after exposure to air., (© 2015 Japanese Society of Animal Science.)

As a forage source for total mixed ration (TMR) silage production, locally produced crop silage is now used in addition to imported hay. This type of TMR ensiling is regarded as a two-step fermentation process; hence, a survey was carried out to determine whether the bacteria in crop silage affect the subsequent TMR ensiling. Fermentation product contents and bacterial community were determined for TMR silage and its ingredient silages collected in August, October and November. August product contained corn, sorghum and Italian ryegrass silages, October product had wheat silage exclusively and November product did not include any crop silages. Acetic acid, lactic acid, 2,3-butanediol and ethanol were predominant fermentation products in corn, sorghum, Italian ryegrass and wheat silages, respectively. Robust lactic acid fermentation was seen in TMR silage, even if acetate-type and alcohol-type silages were mixed as ingredients. The finding that bacterial community of the TMR silage appeared unrelated to those of ingredient silage supported this. Silages of various fermentation types can therefore be formulated without interfering with lactate-type fermentation in TMR silage., (© 2014 Japanese Society of Animal Science.)

The survival of silage lactic acid bacteria (LAB) in the gut of dairy cows was evaluated by examining the LAB communities of silage and gut contents. Samples were collected at 2 different research institutes (Mie and Okayama) that offered total mixed ration (TMR) silage throughout the year. Silage and feces were sampled in August, October, and November at the Mie institute, whereas silage, rumen fluid, and feces were sampled in June and August at the Okayama institute. Denaturing gradient gel electrophoresis using Lactobacillus-specific primers was performed to detect LAB species in the samples. The selected bands were purified for species identification and the band patterns were used for principal component analysis. Lactic acid was the predominant fermentation product in all the TMR silages analyzed, and the lactic acid level tended to be constant regardless of the sampling time and region. A total of 14 LAB species were detected in the TMR silage samples, of which 5 (Lactobacillus acetotolerans, Lactobacillus pontis, Lactobacillus casei, Lactobacillus suebicus, and Lactobacillus plantarum) were detected in the dairy cow feces. Most of the denaturing gradient gel electrophoresis bands for the feces samples were also detected in the rumen fluid, suggesting that any elimination of silage LAB occurred in the rumen and not in the postruminal gut segments. The principal component analysis indicated that the LAB communities in the silage, rumen fluid, and feces were separately grouped; hence, the survival of silage LAB in the cow rumen and lower gut was deemed difficult. It was concluded that, although the gut LAB community is robust and not easily affected by the silage conditions, several LAB species can inhabit both silage and feces, which suggests the potential of using silage as a vehicle for conveying probiotics., (Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

To evaluate the current practice of corn silage management in China, samples of bunker-made silage were collected from 14 farms within a 500-km radius of Beijing for the analysis of fermentation products and bacterial communities. Mean values for dry matter (DM) content were as low as 250 g/kg in both corn stover (St) and whole crop corn (Wc) silages, and pH values averaged 4.48 and 3.73, respectively. Only three of the 14 silages exhibited a lactic-to-acetic acid ratio > 1.0, indicating that the presence of acetic acid was predominant in fermentation. Although 1,2-propanediol content was marginal in most cases (< 5.0 g/kg dry matter (DM)), two Wc silages had 1,2-propanediol levels > 25 g/kg DM. In contrast, 3 St silages had large amounts (> 10 g/kg DM) of butyric acid, and two of the three butyrate silages also had high concentrations of 1-propanol. Denaturing gradient gel electrophoresis analysis demonstrated that the bacterial community appeared similar in 10 out of the 14 silage samples. Bands indicating Lactobacillus buchneri, L. acetotolerans and Acetobacter pasteurianus were found in both the St and Wc silages, accounting for the high acetic acid content found across silage samples., (© 2013 Japanese Society of Animal Science.)

To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3-Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre-ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre-ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre-ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling., (© 2013 Japanese Society of Animal Science.)

Aims: To examine how storage temperatures influence ensiling fermentation, aerobic stability and microbial communities of total mixed ration (TMR) silage., Methods and Results: Laboratory-scale silos were stored at 5, 15, 25 and 35°C for 10, 30 and 90 days. If silage was stored at 5°C, fermentation was weak until day 30, but acceptable lactic acid production was observed on day 90. The ethanol content was higher than the acetic acid content when stored at 15 and 25°C, whereas the ethanol content was lower when stored at 35 than at 25°C. Aerobic deterioration did not occur when silage was exposed to air at the same temperature at which it was stored. Although 10-day silages stored at 5 and 15°C deteriorated when the aerobic stability test was conducted at 25°C, heating was not observed in silages stored at 25 or 35°C or in any 90-day silages regardless of storage temperature. Denaturing gradient gel electrophoresis demonstrated that bands indicative of Lactobacillus plantarum and Lactobacillus delbrueckii were less prominent, while bands indicative of Lactobacillus panis became more distinct in silages stored at high temperatures. Bands of Kluyveromyces marxianus were seen exclusively in silages that were spoiled at 25°C., Conclusion: High ambient temperature enhances acetic acid production in TMR silage. Lactobacillus panis may be associated with changes in the fermentation products due to differences in storage temperature., Significance and Impact of the Study: The role of Lacto. panis in ensiling fermentation and aerobic stability is worth examining., (© 2013 The Society for Applied Microbiology.)

Aims: To determine the survival rate of silage lactic acid bacteria (LAB) in the ruminant gastrointestinal tract., Methods and Results: Wilted Italian ryegrass (Lolium multiflorum Lam.) silage (containing 1·9×10(6) CFU LAB g(-1)) was fed ad libitum to three goats equipped with rumen cannulae. Silage was given alone or with concentrates at a 1:1 ratio on a dry matter basis. Rumen fluid was then obtained 2, 4 and 8h after the morning feeding. Denaturing gradient gel electrophoresis was performed to compare LAB communities in silage, rumen fluid and faeces. The LAB detected in the wilted silage included Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus murinus and Lactobacillus sakei. Bands indicative of Lact. murinus were detected in either the rumen fluid or faeces, whereas the bands indicative of Lact. plantarum, Lact. brevis and Lact. sakei were not. Although the rumen fluid LAB counts and volatile fatty acid concentrations were higher in goats fed silage plus concentrates compared with those fed silage alone, the LAB communities themselves remained unaffected. Sampling times and goat-to-goat variations did not affect the LAB communities found in the rumen fluid., Conclusion: LAB communities found in the gut are not remarkably affected by the consumption of silage LAB, even when the silage is accompanied by concentrates that facilitate gut fermentation., Significance and Impact of the Study: Although silage can improve probiotic function, it may be difficult for silage LAB to survive the digestive process in the ruminant gastrointestinal tract., (© 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.)

Aims: Acetic acid is considered an important preservative in tropical grass ensiling. The objective of the current experiments was to follow the ensiling fermentation of low dry matter (DM) tropical grass as a model to study changes in bacterial communities during acetic acid fermentation., Methods and Results: Direct-cut and wilted guinea grass silage was prepared with and without molasses. A high acetic acid level was observed during the fermentation of direct-cut silage, and long storage increased the butyric acid and ethanol content if molasses was not added. The lactic acid production in wilted silage was greater than the acetic acid production, but prolonged ensiling decreased the lactic to acetic acid ratio regardless of molasses addition. Adding molasses enhanced the lactic acid content in both direct-cut and wilted silage. The bacterial community, identified by denaturing gradient gel electrophoresis, was affected by wilting and molasses addition. Bands for Pantoea sp. and Morganella sp. became faint when acetic acid fermentation was suppressed, and those for Pediococcus pentosaceus and Lactococcus garvieae were detected when lactic acid fermentation was enhanced by wilting and molasses addition. Lactobacillus plantarum and Lactococcus lactis were found throughout the ensiling process in all silage types., Conclusion: Distinct changes occurred in the bacterial community in guinea grass silage because of wilting and molasses addition. These changes could explain how lactic acid fermentation was enhanced but could not help determine which bacteria were associated with enhanced acetic acid fermentation., Significance and Impact of the Study: The study reveals the effects of wilting and molasses during ensiling of low DM tropical grasses and the associated bacteria., (© 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.)

Aims: To monitor variations in the bacterial community and fermentation products of maize silage within and between bunker silos., Methods and Results: Silage samples were collected in 2008 and 2009 from three dairy farms, wherein the farmers arranged for a contractor to produce maize silage using bunker silos. Silage was prepared using a lactic acid bacteria (LAB) inoculant consisting of Enterococcus faecium, Lactobacillus plantarum and Lactobacillus buchneri. Eight samples were collected from each bunker silo; 4 'outer' and 4 'inner' samples were collected from near the top and the bottom of the silo. The dry matter, lactic acid, acetic acid, ethanol, 1-propanol and 1,2-propanediol contents differed between bunker silos in both sampling years. Higher acetic acid, 1-propanol and 1,2-propanediol contents were found in the bottom than the top layers in the 2008 samples, and higher lactic acid content was found in the top than the bottom layers in the 2009 samples. The bacterial community varied more between bunker silos than within a bunker silo in the 2008 samples, whereas differences between the top and the bottom layers were seen across bunker silos in the 2009 samples. The inoculated LAB were uniformly distributed, while several nonconventional silage bacteria were also detected. Lactobacillus acetotolerans, Lactobacillus panis and Acetobacter pasteurianus were detected in both years. Stenotrophomonas maltophilia was detected in the 2008 samples, and Lactobacillus reuteri, Acinetobacter sp. and Rahnella sp. were detected in the 2009 samples., Conclusions: Although differences were seen within and between bunker silos, the bacterial community may indicate a different relationship between bunker silos and sampling locations within a bunker silo from that indicated by the fermentation products., Significance and Impact of the Study: Analysis of bacterial community can help understand how diverse non-LAB and LAB species are involved in the ensiling process of bunker-made maize silage., (© 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.)

Aims: To understand the effects of lactic acid bacteria (LAB) inoculation on fermentation products, aerobic stability and microbial communities of silage., Methods and Results: Wilted Italian ryegrass was stored in laboratory silos with and without inoculation of Lactobacillus rhamnosus and Lactobacillus buchneri. The silos were opened after 14, 56 and 120 days and then subjected to aerobic deterioration for 7 days. Intensive alcoholic fermentation was found in untreated silage; the sum of ethanol and 2,3-butanediol content at day 14 was about 7 times higher than that of lactic and volatile fatty acids. Alcoholic fermentation was suppressed by L. rhamnosus and L. buchneri inoculation and lactic acid and acetic acid became the dominant fermentation products, respectively. Silages were deteriorated in untreated and L. rhamnosus-inoculated silages, whereas no spoilage was found in L. buchneri-inoculated silage. Enterobacteria such as Erwinia persicina, Pantoea agglomerans and Rahnella aquatilis were detected in untreated silage, whereas some of these bacteria disappeared or became faint with L. rhamnosus treatment. When silage was deteriorated, Lactobacillus brevis and Bacillus pumilus were observed in untreated and L. rhamnosus-inoculated communities, respectively. The inoculated LAB species was detectable in addition to untreated bacterial communities. Saccharomyces cerevisiae and Pichia anomala were the main fungi in untreated and L. rhamnosus-inoculated silages; however, P. anomala was not visibly seen in L. buchneri-inoculated silage either at silo opening or after exposure to air., Conclusion: Inoculation with L. rhamnosus can suppress alcoholic fermentation of wilted grass silage with elimination of enterobacteria at the beginning of fermentation. Addition of L. buchneri may improve aerobic stability, with distinct inhibitory effect observed on P. anomala after silo opening., Significance and Impact of the Study: Bacterial and fungal community analyses help us to understand how inoculated LAB can function to improve the fermentation and aerobic stability of silage., (© 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.)

Aims: To characterize the bacterial communities in commercial total mixed ration (TMR) silage, which is known to have a long bunk life after silo opening., Methods and Results: Samples were collected from four factories that produce TMR silage according to their own recipes. Three factories were sampled three times at 1-month intervals during the summer to characterize the differences between factories; one factory was sampled 12 times, three samples each during the summer, autumn, winter and spring, to determine seasonal changes. Bacterial communities were determined by culture-independent denaturing gradient gel electrophoresis. All silages contained lactic acid as the predominant acid, and the contents appeared stable regardless of factories and product seasons. Acetic acid and 1-propanol contents were different between factories and indicated seasonal changes, with increases in warm seasons compared to cool seasons. Both differences and similarities existed among the bacterial communities from each factory and product season. Lactobacillus parabuchneri was found in the products from three of four factories. Various sourdough lactic acid bacteria (LAB) were identified in commercial TMR silage; Lactobacillus panis, Lactobacillus hammesii, Lactobacillus mindensis, Lactobacillus pontis, Lactobacillus frumenti and Lactobacillus farciminis were detected in many products. Moreover, changes owing to product season were distinctive, and Lact. pontis and Lact. frumenti became detectable in summer products., Conclusion: Sourdough LAB are involved in the ensiling of commercial TMR silage. Silage bacterial communities vary more by season than by factory. The LAB species Lact. parabuchneri was detected in the TMR silage but may not be essential to the product's long bunk life after silo opening., Significance and Impact of the Study: Commercial TMR silage resembles sourdough with respect to bacterial communities and long shelf life. The roles of sourdough LAB in the ensiling process and aerobic stability are worth examining., (© 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.)

Aims: To determine the effects of wilting, storage period and bacterial inoculant on the bacterial community and ensiling fermentation of guinea grass silage., Methods and Results: Fermentation products, colony counts and denaturing gradient gel electrophoresis (DGGE) profiles were determined. There was more lactic acid than acetic acid in all silages, but the lactic acid to acetic acid ratio decreased with storage time. This shift from lactic to acetic acid was not prevented even with a combination of wilting and bacterial inoculant. The DGGE analyses suggest that facultatively heterofermentative lactic acid bacteria (Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus pentosus) were involved in the shift to acetic acid fermentation., Conclusions: Lactic acid can dominate the fermentation in tropical grass silage with sufficient wilting prior to ensiling. Prolonged storage may lead to high levels of acetic acid without distinctive changes in the bacterial community., Significance and Impact of the Study: The bacterial community looks stable compared to fermentation products over the course of long storage periods in tropical grass silage. Acetic acid fermentation in tropical grass silage can be a result of the changes in bacterial metabolism rather than community structure.

Wet brewers grains and soybean curd residue were stored in laboratory-scale silos without (BG and SC silages, respectively) or with other ingredients as total mixed rations (BGT and SCT silages, respectively). Silages were opened after 14 and 56 d, and microbial counts, fermentation products, and aerobic stability were determined. Denaturing gradient gel electrophoresis was carried out to examine bacterial communities, and several bacteria that appeared to be involved in fermentation were identified. Lactic acid content was greater in SCT than in BGT silage, but lower in SC than in BG silage. Ethanol content was greater in BG than in SC regardless of silage type. Aerobic deterioration occurred promptly in ensiling materials (nonensiled by-products and total mixed ration mixtures) and in silages stored alone; however, SCT and BGT silages resisted deterioration and no heating was found for more than 5.5 d regardless of storage period. Silages were stable even with high yeast populations at silo opening, whereas prolonged ensiling decreased yeast counts in the 2 total mixed ration silages. The denaturing gradient gel electrophoresis profiles appeared similar between SCT and BGT silages but not between SC and BG silages. Weissella spp. and Lactobacillus brevis were common in aerobically stable SCT and BGT silages, and Lactobacillus buchneri was detected only in BGT silage. Both L. brevis and L. buchneri were found in silage but not in ensiling materials. Several other lactic acid bacteria were also identified in SCT and BGT silages, but did not appear to be related to fermentation and aerobic stability.

Aims: To investigate the effects of inoculating Lactobacillus casei or Lacobacillus buchneri on the production of biogenic amines (BA) in silage., Methods and Results: Wilted festulolium (Lolium perenne x Festuca pratensis), whole crop maize or a total mixed ration, consisting of wet brewer grains, lucerne hay, cracked maize, sugarbeet pulp, soyabean meal and molasses, was ensiled with or without the inoculation of either L. casei (>10(6) CFU g(-1)) or L. buchneri (>10(6) CFU g(-1)). Silages were opened after 60 days of storage, and the concentrations of histamine, tyramine, putrescine and cadaverine were determined. The inoculation of L. casei decreased all the BA regardless of the silage type. The effects of L. buchneri varied between the three silages; the tyramine and putrescine were increased in maize but were lowered in festulolium. Histamine was reduced in festulolium and the by-products, whereas no change was found in the maize silage. None of the inoculant strains produced the four BA in a synthetic medium, accounting for the actual ensiling except for tyramine and putrescine in maize., Conclusions: Wide variation would be found in the production of BA owing to the ensiling materials. The inoculation of L. casei can lower the BA concentration, while the effects of L. buchneri may vary considerably. The screening of BA-producing activity may help to reduce the risk of BA contamination in inoculated silage., Significance and Impact of the Study: Strains of decarboxylase-negative L. buchneri can enhance the aerobic stability of silage without a concern regarding the large production of putrefactive BA.

Aims: To evaluate the fermentation characteristics and the effects of Lactobacillus buchneri inoculation in ensiling whole crop rice., Methods and Results: Laboratory-scale silages were prepared from whole crop rice harvested at yellow-ripe stage. The crop was ensiled for 2 months with and without inoculation of L. buchneri at 10(4), 10(5) and 10(6) CFU g(-1). The effect of prolonged ensiling was also studied by using the same crop; the silos were opened at 1, 3, 6 and 12 months, while the inoculation was made at 10(5) CFU g(-1). Enhanced alcoholic fermentation was found in untreated silage; the sum of ethanol and 2,3-butanediol were seven times higher at 2 months than those of lactic and volatile fatty acids, while the differences were diminished at 12 months owing to the reduction of ethanol in the late ensiling period. Inoculation of L. buchneri inhibited the alcohols; however, ethanol yet prevailed over the fermentation until 6 months, after which acetic acid became the main product in the inoculated silage. Regardless of inoculation and ensiling period, yeasts were not found in whole crop rice silage., Conclusions: Substantial amounts of ethanol and 2,3-butanediol would be produced in silage prepared from whole crop rice. The alcoholic fermentation can be suppressed when inoculated with L. buchneri., Significance and Impact of the Study: Inoculation of L. buchneri could be an option to prevent ethanol fermentation in silage.

Whole crop corn (DM 29.2%) and a total mixed ration (TMR, DM 56.8%) containing wet brewers grains, alfalfa hay, dried beet pulp, cracked corn, soybean meal, and molasses at a ratio of 5:1:1:1:1:1 on fresh weight basis, were ensiled with and without Lactobacillus casei or Lactobacillus buchneri in laboratory silos. The effects of inoculation on microbial counts, fermentation products, and aerobic stability were determined after 10 and 60 d. Untreated corn silage was well preserved with high lactic acid content, whereas large numbers of remaining yeasts resulted in low stability on exposure to air. Inoculation with L. casei suppressed heterolactic fermentation, but no improvements were found in aerobic stability. The addition of L. buchneri markedly enhanced the aerobic stability, while not affecting the DM loss and NH3-N production. Large amounts of ethanol were found when the TMR was ensiled, and the content of ethanol overwhelmed that of lactic acid in untreated silage. This fermentation was related to high yeast populations and accounted for a large loss of DM found in the initial 10 d. The ethanol production decreased when inoculated with L. casei and L. buchneri, but the effects diminished at 60 d of ensiling. Inoculation with L. buchneri lowered the yeasts in TMR silage from the beginning of storage; however, the populations decreased to undetectable levels when stored for 60 d, regardless of inoculation. No heating was observed in TMR silage during aerobic deterioration test for 7 d. This stability was achieved even when a high population of yeasts remained and was not affected by either inoculation or ensiling period. The results indicate that inoculation with L. buchneri can inhibit yeast growth and improve aerobic stability of corn and TMR silage; however, high stability of TMR silage can be obtained even when no treatments were made and high population (>10(5) cfu/g) of yeasts were detected.

Aims: To assess the effects of inoculation of Lactobacillus buchneri on the ensiling properties and aerobic stability of maize silage., Methods and Results: Chopped whole crop maize was ensiled in 0.5 litre airtight polyethylene bottles (0.4 kg per bottle) and in double-layered, thin polyethylene bags (15 kg per bag), with or without inoculation of Lact. buchneri. The silos were stored for two to four months and the chemical composition, microbial numbers and aerobic stability were determined. Inoculation lowered lactic acid and yeasts, and increased acetic acid and pH value, resulting in improved aerobic stability of the silages. Inoculated silages produced 1,2-propanediol, the content of which increased as ensiling was prolonged, and nearly 50 g kg-1 dry matter had accumulated after four months of storage. The effects of inoculation, however, were much less pronounced in silages prepared in bags. Mannitol was found in all silages; the production was lowered by Lact. buchneri treatment and appeared to be unrelated to the accumulation of 1,2-propanediol., Conclusions: Inoculation of Lact. buchneri occasionally causes accumulation of 1,2-propanediol in silages without further degradation into propionic acid and 1-propanol., Significance and Impact of the Study: Substantial amounts of 1,2-propanediol could be consumed by ruminants when fed on silages inoculated with Lact. buchneri. In addition to increasing acetic acid, attention needs to be paid to 1,2-propanediol because the two fermentation products might affect the intake and utilization of silage-based diets.

We investigated the effects of the predominant lactic acid bacteria (LAB) on the fermentation characteristics and aerobic stability of total mixed ration (TMR) silage containing soybean curd residue (SC-TMR silage). The SC-TMR materials were ensiled in laboratory silos for 14 or 56 days. LAB predominant in SC-TMR silage were identified (Exp. 1). Lactobacillus fermentum (L. fermentum) and Streptococcus bovis (S. bovis) were found in the untreated materials, Leuconostoc pseudomesenteroides (L. pseudomesenteroides) in 14-day silage and Lactobacillus plantarum (L. plantarum) in all silages. Pediococcus acidilactici (P. acidilactici), Lactobacillus paracasei (L. paracasei), and Lactobacillus brevis (L. brevis) formed more than 90% of the isolates in 56- day silage. Italian ryegrass and whole crop maize were inoculated with P. acidilactici and L. brevis isolates and the fermentation and aerobic stability determined (Exp. 2). Inoculation with P. acidilactici and L. brevis alone or combined improved the fermentation products in ryegrass silage and markedly enhanced its aerobic stability. In maize silage, P. acidilactici and L. brevis inoculation caused no changes and suppressed deterioration when combined with increases in acetic acid content. The results indicate that P. acidilactici and L. brevis may produce a synergistic effect to inhibit SC-TMR silage deterioration. Further studies are needed to identify the inhibitory substances, which may be useful for developing potential antifungal agents. [ABSTRACT FROM AUTHOR]