The effect of treating whole-plant barley with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for dairy cows

Nutritive value, silage fermentation characteristics, and aerobic stability of grass-legume round-baled silages at differing moisture concentrations with and without manure fertilization and microbial inoculation

For baled silages, production of clostridial fermentation products can be exacerbated by exceeding normal moisture targets (45% to 55%), and/or by the application of dairy slurry before harvest. Our objectives were to test a microbial inoculant as a mitigant of clostridial products in high-moisture, grass-legume (52% ± 13.8% cool-season grasses, 44.0% ± 14.0% legumes [predominately alfalfa]) baled silages in swards that were fertilized with dairy slurry. A secondary objective was to examine the effects of bale moisture and inoculation on the aerobic stability of these fermented silages following exposure to air. After the first-cutting was removed, three manure treatments were applied as a whole-plot factor: 1) control (no manure); 2) slurry applied immediately to stubble (63,250 L/ha); or 3) slurry applied after a 1-wk delay (57,484 L/ha). An interactive arrangement of bale moisture (64.1% or 48.4%) and inoculation (yes or no) served as a subplot term in the experiment. The inoculant contained both homolactic (Lactococcus lactis 0224) and heterolactic (Lactobacillus buchneri LB1819) bacteria. The experimental design was analyzed as a randomized complete block with four replications, and the study included 48 experimental units (1.2 × 1.2-m round bales). Total fermentation acids were affected (P ≤ 0.021) by slurry application strategies, but this was likely related to inconsistent bale moisture across slurry-application treatments. Concentrations of butyric acid were low, and there were no detectable contrasts comparing manure treatments (mean = 0.05%; P ≥ 0.645). Bale moisture affected all measures of fermentation, with bales made at 64.1% moisture exhibiting a more acidic final pH (4.39 vs. 4.63; P < 0.001), less residual water-soluble carbohydrates (2.1% vs. 5.1%; P < 0.001), as well as greater lactic acid (4.64% vs. 2.46%; P < 0.001), acetic acid (2.26% vs. 1.32%; P < 0.001), and total fermentation acids (7.37% vs. 3.97%; P < 0.001). Inoculation also reduced pH (4.47 vs. 4.56; P = 0.029), and increased acetic acid (1.97% vs. 1.61%; P < 0.001) and 1,2-propanediol (1.09% vs. 0.72%; P < 0.001) compared to controls. During a 34-d aerobic exposure period, maximum surface bale temperatures were not affected (P ≥ 0.186) by any aspect of treatment, likely due to the prevailing cool ambient temperatures; however, yeast counts were numerically lower in response to greater (P < 0.001) production of acetic acid that was stimulated by both high bale moisture and inoculation.

Meta-analysis of effects of inoculation with Lactobacillus buchneri, with or without other bacteria, on silage fermentation, aerobic stability, and performance of dairy cows

A meta-analysis of 158 peer-reviewed articles was conducted to examine effects of inoculation with Lactobacillus buchneri (LB)-based inoculants (LBB) that did or did not include homolactic or obligate heterolactic bacteria on silage fermentation and aerobic stability. A complementary meta-analysis of 12 articles examined LBB inoculation effects on dairy cow performance. Raw mean differences between inoculant and control treatment means weighted by inverse variance were compared with a hierarchical effects model that included robust variance estimation. Meta-regression and subgrouping analysis were used to identify effects of covariates including forage type, application rate (≤10⁴, 10⁵, 10⁶, or ≥ 10⁷ cfu/g as fed), bacteria type (LB vs. LB plus other bacteria), enzyme inclusion, ensiling duration, and silo type (laboratory or farm scale). Inoculation with LBB increased acetate (62%), 1, 2 propanediol (364%) and propionate (30%) concentration and aerobic stability (73.8%) and reduced lactate concentration (7.2%), yeast counts (7-fold) and mold counts (3-fold). Feeding inoculated silage did not affect milk yield, dry matter intake, and feed efficiency in lactating dairy cows. However, forage type, inoculant composition, and dose effects on silage quality measures were evident. Inoculation with LBB increased aerobic stability of all silages except tropical grasses. Adding obligate homolactic or facultative heterolactic bacteria to LB prevented the small increase in DM losses caused by LB alone. The 10⁵ and 10⁶ cfu/g rates were most effective at minimizing DM losses while aerobic stability was only increased with 10⁵, 10⁶, and ≥ 10⁷ cfu/g rates. Inoculation with LBB increased acetate concentration, reduced yeast counts and improved aerobic stability but did not improve dairy cow performance.

Using molecular microbial ecology to define differential responses to the inoculation of barley silage

Previously, we investigated the impact of a mixed Lactobacillus buchneri, Lactobacillus plantarum, and Lactobacillus casei inoculant on fermentation and aerobic stability of barley silage over two years in 2009 and 2010. In 2009, a classical response to inoculation was obtained with an increase in acetic acid concentration of silage ensiled in both mini- and bag silos. In 2010, this classical response was not observed in mini-silos but was observed in bag silos. The objective of this study was to determine if molecular microbial ecology could explain the differential responses to the inoculation of barley silage between the two years. The Illumina MiSeq sequencing results showed that inoculation increased Lactobacillus and lowered Pediococcus, Weissella, and Leuconostoc in both types of silos in 2009. However, a similar trend was not observed in mini-silos, but was instead observed in bag silos in 2010. Inoculation did not alter the core fungal community in either silo type in either year. Cladosporium, Leptosphaeria, and Cryptococcus were abundant in fresh forage, but were superseded by Pichia and Kazachstania after ensiling. Our results suggest that changes in silage chemistry corresponded to differences observed in microbial ecology. Inoculation may have less impact when using more mature crops with shorter ensiling times.

Morphophysical reaction of Hordeum vulgare to the influence of microbial preparations

Bacterial preparations contribute to the digestion of mineral nutrition, have antifungicidal activity, increase the grain productivity and biomass of cultivated crops. We studied the influence of microbiological preparations developed on the basis of microorganisms Bacillus subtilis and Lactobacillus buchneri on the growth processes, photosynthetic parameters and grain productivity of barley (Hordeum vulgare L.) of Sonet variety. The experiments were performed in 2019 in the North-West of the Russian Federation. The biological preparations were introduced by soaking seeds and treatment of the plants in the phase of third leaf with solutions of the preparations in the concentration of 1 mL/L. The laboratory surveys revealed the positive effect of the biological preparations on germination rate and energy of germination of seeds. Field trials were conducted on micro plots in six replications. During field experiments, we determined that introduction of biological preparations led to significant increase in the leaf area in the experimental plants (to 64.5%), increase in average daily growth gains (to 82.9%) and accumulation of biomass (to 73.1%). Somewhat higher efficiency was exerted by the biological preparation developed on the basis of a strain of L. buchneri. Perhaps, such effect takes place due to higher activity of pigment units of phytohormones of the auxin group. In our opinion, biological preparations accelerate the completion of the ontogenesis phases, thus the plants more rapidly achieve their genetically programmed sizes and transform to the stage of ear-formation. The studied biological preparations increased the coefficient of agricultural use of plants, and grain productivity of barley by up to 15.8%, and nutritional value remained. Microbial preparations on the basis of B. subtilis and L. buchneri exhibited efficiency, and their trials shall be continued on other crops on industrial scales.

Effect of temperature on single- and mixed-strain fermentation of ruminant feeds

Use of raw feedstuffs for livestock is limited by low digestibility. Recently, fermentation of feedstuffs has been highlighted as a new way to improve nutrient absorption through the production of organic acids using inoculated microorganisms, which can also play a probiotic role. However, standard procedures for feedstuff fermentation have not been clearly defined because the process is influenced by climatic variation, and an analytical standard for fermented feedstuffs is lacking. This study aimed to evaluate the microbiological and biochemical changes of feedstuffs during fermentation at temperatures corresponding to different seasons (10°C, 20°C, 30°C, and 40°C). We also investigated the effects of yeast, lactic acid bacteria (LAB), and Bacillus spp. on fermentation and determined the results of their interactions during fermentation. The viable cells were observed within 8 days in single-strain fermentation. However, when feedstuffs were inoculated with a culture of mixed strains, LAB were predominant at low temperatures (10°C and 20°C), while Bacillus spp. was predominant at high temperatures (30°C and 40°C). A significant drop in pH from 6.5 to 4.3 was observed when LAB was the dominant strain in the culture, which correlated with the concentrations of lactic acid. Slight ethanol production was detected above 20°C regardless of the incubation temperature, suggesting active metabolism of yeast, despite this organism making up a marginal portion of the microbes in the mixed culture. These results suggested that fermentation temperature significantly affects microbiological profiles and biochemical parameters, such as pH and the lactic acid concentration, of fermented feedstuffs. Our data provide valuable information for the determination of industrial standards for fermented feedstuffs.

Use of crude glycerine and microbial inoculants to improve the fermentation process of Tifton 85 haylages

The increase in haylage production leads to the search for additives that improve its fermentation and nutritional value. This study aimed to assess the effect of adding crude glycerine and microbial additives on losses, fermentation parameters and nutritional value of haylage. The treatments were composed of three doses of crude glycerine (0, 60 and 120 g/kg forage) and three types of inoculation (control (distilled water), SIL (Lactobacillus plantarum 2.6 × 10¹⁰ CFU/g and Pediococcus pentosaceus 2.6 × 10¹⁰ CFU/g) and INC (Bacillus subtilis 2.0 × 10⁹ CFU/g, Lactobacillus plantarum 8.0 × 10⁹ CFU/g and Pediococcus acidilactici 1.0 × 10¹⁰ CFU/g)). A negative linear effect was observed in the fibre fraction contents of the haylages as a function of crude glycerine addition, which contributed to similarly increasing dry matter in vitro digestibility coefficients. The use of inoculants also resulted in haylages with higher digestibility coefficients of 635.1 and 646.8 g/kg dry matter (DM) in the treatments inoculated with INC and SIL, respectively. Fermentation losses were reduced by adding crude glycerine and were not impacted by the microbial inoculants. Higher lactic acid productions were obtained as a function of crude glycerine doses. Acetic acid productions decreased from 29.3 g/kg DM to 19.2 g/kg DM between crude glycerine doses of 0 and 120 g/kg forage, respectively. SIL led to the highest lactic acid productions compared to INC and the control. Crude glycerine improves the fermentation parameters and nutritional value of haylages. However, the microbial inoculants had little impact on the parameters assessed.

Symposium review: Technologies for improving fiber utilization

The forage lignocellulosic complex is one of the greatest limitations to utilization of the nutrients and energy in fiber. Consequently, several technologies have been developed to increase forage fiber utilization by dairy cows. Physical or mechanical processing techniques reduce forage particle size and gut fill and thereby increase intake. Such techniques increase the surface area for microbial colonization and may increase fiber utilization. Genetic technologies such as brown midrib mutants (BMR) with less lignin have been among the most repeatable and practical strategies to increase fiber utilization. Newer BMR corn hybrids are better yielding than the early hybrids and recent brachytic dwarf BMR sorghum hybrids avoid lodging problems of early hybrids. Several alkalis have been effective at increasing fiber digestibility. Among these, ammoniation has the added benefit of increasing the nitrogen concentration of the forage. However, few of these have been widely adopted due to the cost and the caustic nature of the chemicals. Urea treatment is more benign but requires sufficient urease and moisture for efficacy. Ammonia-fiber expansion technology uses high temperature, moisture, and pressure to degrade lignocellulose to a greater extent than ammoniation alone, but it occurs in reactors and is therefore not currently usable on farms. Biological technologies for increasing fiber utilization such as application of exogenous fibrolytic enzymes, live yeasts, and yeast culture have had equivocal effects on forage fiber digestion in individual studies, but recent meta-analyses indicate that their overall effects are positive. Nonhydrolytic expansin-like proteins act in synergy with fibrolytic enzymes to increase fiber digestion beyond that achieved by the enzyme alone due to their ability to expand cellulose microfibrils allowing greater enzyme penetration of the cell wall matrix. White-rot fungi are perhaps the biological agents with the greatest potential for lignocellulose deconstruction, but they require aerobic conditions and several strains degrade easily digestible carbohydrates. Less ruminant nutrition research has been conducted on brown rot fungi that deconstruct lignocellulose by generating highly destructive hydroxyl radicals via the Fenton reaction. More research is needed to increase the repeatability, efficacy, cost effectiveness, and on-farm applicability of technologies for increasing fiber utilization.

Silage review: Silage feeding management: Silage characteristics and dairy cow feeding behavior

Feeding environment and feed accessibility influence the dairy cow's response to the ration and forage composition. Fiber content, physical form, and fermentability influence feeding behavior, feed intake, and overall cow metabolic and lactational responses to forage. It is possible to vary eating time of lactating dairy cattle by over 1 h/d by changing dietary silage fiber content, digestibility, and particle size. Optimizing silage particle size is important because excessively long particles increase the necessary chewing to swallow a bolus of feed, thereby increasing eating time. Under competitive feeding situations, excessively coarse or lower fiber digestibility silages may limit DMI of lactating dairy cows due to eating time requirements that exceed available time at the feed bunk. Additionally, greater silage particle size, especially the particles retained on the 19-mm sieve using the Penn State Particle Separator, are most likely to be sorted. Silage starch content and fermentability may influence ruminal propionate production and thereby exert substantial control over meal patterns and feed consumption. Compared with silage fiber characteristics, relatively little research has assessed how silage starch content and fermentability interact with the feeding environment to influence dairy cow feeding behavior. Finally, voluminous literature exists on the potential effects that silage fermentation end products have on feeding behavior and feed intake. However, the specific mechanisms of how these end products influence behavior and intake are poorly understood in some cases. The compounds shown to have the greatest effect on feeding behavior are lactate, acetate, propionate, butyrate, ammonia-N, and amines. Any limitation in the feeding environment will likely accentuate the negative response to poor silage fermentation. In the future, to optimize feeding behavior and dry matter intake of silage-based diets fed to dairy cattle, we will need to consider the chemical and physical properties of silage, end products of silage fermentation, and the social and physical components of the feeding environment.

Phenotypic and genotypic diversity of Lactobacillus buchneri strains isolated from spoiled, fermented cucumber

Lactobacillus buchneri is a Gram-positive, obligate heterofermentative, facultative anaerobe commonly affiliated with spoilage of food products. Notably, L. buchneri is able to metabolize lactic acid into acetic acid and 1,2-propanediol. Although beneficial to the silage industry, this metabolic capability is detrimental to preservation of cucumbers by fermentation. The objective of this study was to characterize isolates of L. buchneri purified from both industrial and experimental fermented cucumber after the onset of secondary fermentation. Genotypic and phenotypic characterization included 16S rRNA sequencing, DiversiLab® rep-PCR, colony morphology, API 50 CH carbohydrate analysis, and ability to degrade lactic acid in modified MRS and fermented cucumber media. Distinct groups of isolates were identified with differing colony morphologies that varied in color (translucent white to opaque yellow), diameter (1 mm-11 mm), and shape (umbonate, flat, circular or irregular). Growth rates in MRS revealed strain differences, and a wide spectrum of carbon source utilization was observed. Some strains were able to ferment as many as 21 of 49 tested carbon sources, including inulin, fucose, gentiobiose, lactose, mannitol, potassium ketogluconate, saccharose, raffinose, galactose, and xylose, while others metabolized as few as eight carbohydrates as the sole source of carbon. All isolates degraded lactic acid in both fermented cucumber medium and modified MRS, but exhibited differences in the rate and extent of lactate degradation. Isolates clustered into eight distinct groups based on rep-PCR fingerprints with 20 of 36 of the isolates exhibiting >97% similarity. Although isolated from similar environmental niches, significant phenotypic and genotypic diversity was found among the L. buchneri cultures. A collection of unique L. buchneri strains was identified and characterized, providing the basis for further analysis of metabolic and genomic capabilities of this species to enable control of lactic acid degradation in fermented plant materials.

Effect of the inoculation of sugarcane silage with Lactobacillus hilgardii and Lactobacillus buchneri on feeding behavior and milk yield of dairy cows

Despite its low NDF digestibility, sugarcane is an option for feeding dairy cattle in tropical regions. We evaluated the effect of sugarcane silages inoculated with CCMA 0170 (LH; an epiphytic bacteria isolated from sugarcane) or with NCIMB 40788 (LB; a commercial strain isolated from temperate grasses) on dairy cow performance and feeding behavior. The microbial inoculums were previously grown in the laboratory to obtain 5 log cfu/g of fresh forage. Nine tons of each inoculated silage and a noninoculated control silage (CON) were harvested from the same field and stored for at least 35 d in experimental 20 × 2.1 × 0.4 m bunker silos. Fifteen Holstein cows in late lactation (336 ± 175 days in milk at the start of the experiment) received the treatments in five 3 × 3 Latin squares with 21-d periods. The diets contained 20% of DM of sugarcane silage and 41% of DM of corn silage. Milk yield was increased from 18.0 kg/d for CON to18.8 kg/d for LH, but LB did not elicit a detectable increase in milk yield (18.1 kg/d). The daily yields of fat, protein, lactose, and total solids were increased by LH. Daily DMI and total tract apparent digestibility of nutrients did not differ among treatments. Both inoculated silages reduced acetate and increased butyrate proportions in ruminal VFA, but only LH silage reduced the acetate to propionate ratio (3.0 vs 3.3). First meal duration was shorter for CON compared to LH and LB. The proportion of daily intake between 0700 and 1300 h tended to be increased, and the proportion between 1900 and 0700 h was reduced by LH. The inoculation of sugarcane silage with affected rumen fermentation profile and feeding behavior of late lactation dairy cows, increasing the yield of milk solids.

Effects of Different Cutting Height on Nutritional Quality of Whole Crop Barley Silage and Feed Value on Hanwoo Heifers

The present study evaluated the effects of different cutting height on nutritive value, fermentation quality, in vitro and in vivo digestibility of whole crop barley silage. Whole crop barley forage (Yuyeon hybrid) was harvested at height of 5, 10, and 15 cm from the ground level. Each cutting height was rolled to make round bale and ensiled for 100 days. After 100 days of ensiling, pH of silage was lower (p<0.05) in 5 cm, but no difference between 10 and 15 cm of cutting height. The content of lactate and lactate to acetate ratio were increased (p<0.05) in 5 cm of cutting height, whereas the acetate content was higher (p<0.05) in 10 and 15 cm than that of 5 cm cutting height. Aerobic stability was greater (p<0.05) in silages of 10 and 15 cm of cutting height. Three total mixed rations (TMR) were formulated with silages from the three different cutting heights (TMR5, TMR10, and TMR15) incorporated as forage at 70:30 ratio with concentrate (dry matter [DM] basis). In vitro dry matter digestibility was higher (p<0.05) in the TMR5 and TMR10 than that in TMR15, whereas in vitro neutral detergent fiber digestibility was higher (p<0.05) in the TMR10 and TMR15 than that in TMR5. Concentration of NH3-N was highest (p<0.05) in the TMR10 followed by TMR15 and TMR5. Total volatile fatty acid was decreased (p<0.05) with increased cutting height. The digestibility of DM and neutral detergent fiber were highest (p<0.05) in TMR15, than those in TMR5 and TMR10, whereas acid detergent fiber digestibility was higher (p<0.05) in TMR5 than that in TMR10. The results showed that increasing cutting height, at least up to 10 to 15 cm, of whole crop barley forage at harvest (Yuyeon) may be beneficial for making silage for TMR formulation and increasing digestibility of DM and NDF.

Effects of microbial additives on chemical composition and fermentation characteristics of barley silage

This study examined the effects of bacterial inoculants on chemical composition and fermentation indices of barley silage. Barley forage (Youngyang) was harvested at 24% dry matter (DM) and wilted to 47.9% DM. The wilted barley forage was chopped to 3–5 cm length and applied with no inoculant (CON), L. plantarum (1×10¹⁰ cfu/g, LP) or Effective Microorganisms (0.5×10⁹ cfu/g, EM). Then the forages were ensiled in four replications for each treatment in 20 L mini silos and stored for 100 days. The contents of crude protein and ether extract were higher in CON silage ensiled for 100-d, while the contents of DM and crude ash were higher in EM silage (p<0.05). The contents of ADF, NDF and hemicellulose as well as the in vitro DM digestibility were not affected by microbial inoculation (p>0.05). The pH, ammonia-N concentration and lactate to acetate ratio were higher (p<0.05) in CON silage, while lactate concentrations were higher (p<0.05) in CON and LP silage. Acetate concentration and lactic acid bacteria was increased (p<0.05) by both inoculants (LP and EM), but propionate concentration and yeast was increased (p<0.05) by EM and LP, respectively. These results indicated that the fermentation quality of barley silage was improved by the application of bacterial inoculants.

Effects of fermented persimmon extract supplements on chemical composition and fermentation characteristics of barley silage

This study was conducted to estimate the effect of fermented persimmon extract (FPE) supplementation levels on chemical composition and fermentation characteristics of barley silage. Barley forage was harvested at 25% dry matter and chopped to 5 cm lengths. The FPE was applied at 0, 0.4, 0.8 and 1.6 g/kg of barley forage (fresh weight basis). After sub-sampling of barley forages (0 day), a total of 64 laboratory mini silos (5 kg capacity) were ensiled to generate quadruplicate data from each of four treatments for four ensiling durations (2, 6, 40 and 120 days). The chemical compositions and in vitro digestibility of barley forage (0 day) were not affected by FPE supplementation. However, the content (L, P = 0.035) and in vitro digestibility (L, P = 0.041) of neutral detergent fiber on 120-day barley silage decreased by increasing FPE supplements. Acetate content of barley silage ensiled for 120 days increased (Q, P = 0.004) by increasing FPE supplements, whereas pH (L, P < 0.001), lactate content (Q, P < 0.001) and lactate-to-acetate ratio (Q, P < 0.001) decreased. These results indicate that addition of FPE can increase the acetate content which has potential to increase aerobic stability.

Características da fermentação e estabilidade aeróbia de silagens de milho inoculadas com Bacillus subtilis

Objetivou-se avaliar os efeitos da inoculação de Bacillus subtilis sobre as características e perdas ocorridas na fermentação, no desenvolvimento de leveduras e fungos filamentosos e na estabilidade aeróbia de silagens de milho. Estudou-se o milho híbrido 2B655, no qual avaliaram-se os seguintes tratamentos: silagem sem inoculação de B. subtilis e silagens inoculadas com B. subtilis nas concentrações de 5x10(4); 1x10(5) e 5x10(5)UFC/g de forragem. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema de parcelas subdivididas, em que as silagens constituíram as parcelas e os tempos de exposição aeróbia as subparcelas, com quatro repetições. Os dados obtidos foram submetidos à análise de variância por meio do software SISVAR®, bem como aplicou-se a análise de regressão a 5% de significância. A aplicação de B. subtilis não alterou as características químicas e as perdas no processo de fermentação da silagem de milho. A contagem de leveduras na abertura dos silos foi reduzida, assim como a população de fungos filamentosos diminuiu durante a exposição aeróbia, o que implicou em menores valores de pH e resultou em maior estabilidade aeróbia, devido à utilização da maior dose de B. subtilis. A inoculação de Bacillus subtilis na concentração de 5x10(5)UFC/g de forragem controla o crescimento dos micro-organismos deterioradores e melhora a estabilidade aeróbia da silagem de milho, a manter os valores de pH mais estáveis na fase de pós-abertura dos silos.

Technological innovations in silage production and utilization

Technology innovation is the process through which new technologies are developed. Silage research addresses the various agronomical, biochemical, microbiological, nutritional and engineering aspects of the process. Forage harvesters, additives (inoculants), and plastic films for sealing are important recent developments. The corn silage is the major source of energy in rations, but recently the use of other ensiled crops, such as sugarcane and legumes, has been increased. Two newer ensiling techniques are the pressed bag and the wrapped bale. Polyethylene film has been the most common method used to protect silage near the surface, but new plastic films are available or in the process of development. A co-extruded polyethylene-polyamide film and new polyvinyl alcohol film also have been used to seal corn silage. Various types of additives have been developed in order to improve the ensiling process. Lactobacillus buchneri, that is an obligate heterolactic acid bacterium, might improve the aerobic stability of silages and have been more effective in corn silage than in other silages. Energy production from silage has also attracted much interest in recent years, as perennial grasses that have been stored as biomass to produce biofuels in the United States, and silage as feedstock for biogas in Europe.

Use of thermal imaging and the in situ technique to assess the impact of an inoculant with feruloyl esterase activity on the aerobic stability and digestibility of barley silage

Addah, W., Baah, J., Okine, E. K. and McAllister, T. A. 2012. Use of thermal imaging and the in situ technique to assess the impact of an inoculant with feruloyl esterase activity on the aerobic stability and digestibility of barley silage. Can. J. Anim. Sci. 92: 381–394. Feruloyl esters limit the digestibility of forages, a constraint that may be overcome if additives with feruloyl esterase (FE) activity are applied to forage. This study determined if a FE-producing strain of Lactobacillus buchneri LN4017 in combination with Lactobacillus plantarum LP7109 and Lactobacillus casei LC3200 improves fermentation, aerobic stability and in situ fibre disappearance of whole-crop barley silage. Barley forage (350 g kg−1 DM) was either uninoculated (UN) or inoculated (1.3×105 CFU g−1 fresh forage; IN) and ensiled in Ag-Bag® silos. Bags were opened after 90 d of ensiling. Samples were collected on day 95, 123 and 175 for determination of fermentation characteristics. Surface temperature of the face of each bag was measured over 3 d using a thermal infrared camera. Ruminal in situ DM and NDF disappearance (aNDFD) of silage and rumen fermentation patterns were measured using three ruminally cannulated heifers. The L. buchneri-treated silage possessed a higher acetic acid concentration than UN (48.8 vs.18.4 g kg−1 DM). The temperature at the face of IN was lower than UN immediately upon exposure and after 3 d of aerobic exposure. Inoculation increased (P=0.01) 24-h and 48-h aNDFD with a trend towards a glucogenic pattern of ruminal fermentation in heifer compared with UN silage. There was evidence that the FE-producing inoculant improved aerobic stability and aNDFD of whole-crop barley silage.

Perdas fermentativas e estabilidade aeróbia de silagens de milho inoculadas com bactérias ácido-láticas em diferentes estádios de maturidade

Objetivou-se, nesta pesquisa, avaliar o efeito de inoculantes bacterianos em silagens produzidas com plantas de milho em diferentes estádios de maturidade quanto às perdas fermentativas e estabilidade aeróbia. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 3x5, e avaliaram-se dois inoculantes (Silobac® e Maize All®) e uma silagem controle em 5 estádios de maturação fisiológica do milho, com 4 repetições. Verificou-se efeito positivo dos inoculantes quanto às perdas fermentativas, e a adição de Silobac® e Maize All® promoveram perda de matéria seca (PMS) 1,78 e 1,75 pontos percentuais a menos que a silagem controle (7,95%). As silagens produzidas com 2/3 de linha de leite e camada negra (CN) apresentaram menor PMS, o que se deve principalmente a menor produção de efluente. A silagem que levou maior tempo para apresentar quebra da estabilidade aeróbia foi aquela produzida a partir de plantas de milho no estádio camada negra e inoculada com Maize All®, ao passo que se notou menor estabilidade para outras silagens inoculadas com esse mesmo produto em virtude do aumento no teor de umidade das silagens. Os inoculantes utilizados neste trabalho são eficientes em diminuir as perdas de MS durante o processo fermentativo, contudo, contribuem com maior aporte de nutrientes nas silagens, o que resulta em menor estabilidade após a abertura dos silos. Silagens produzidas com maior concentração de MS apresentam menores perdas de MS durante a fermentação, assim como são mais estáveis em contato com o oxigênio.

Insights into the completely annotated genome of Lactobacillus buchneri CD034, a strain isolated from stable grass silage

Lactobacillus buchneri belongs to the group of heterofermentative lactic acid bacteria and is a common member of the silage microbiome. Here we report the completely annotated genomic sequence of L. buchneri CD034, a strain isolated from stable grass silage. The whole genome of L. buchneri CD034 was sequenced on the Roche Genome Sequencer FLX platform. It was found to consist of four replicons, a circular chromosome, and three plasmids. The circular chromosome was predicted to encode 2319 proteins and contains a genomic island and two prophages which significantly differ in G+C-content from the remaining chromosome. It possesses all genes for enzymes of a complete phosphoketolase pathway, whereas two enzymes necessary for glycolysis are lacking. This confirms the classification of L. buchneri CD034 as an obligate heterofermentative lactic acid bacterium. A set of genes considered to be involved in the lactate degradation pathway and genes putatively involved in the breakdown of plant cell wall polymers were identified. Moreover, several genes encoding putative S-layer proteins and two CRISPR systems, belonging to the subclasses I-E and II-A, are located on the chromosome. The largest plasmid pCD034-3 was predicted to encode 57 genes, including a putative polysaccharide synthesis gene cluster, whereas the functions of the two smaller plasmids, pCD034-1 and pCD034-2, remain cryptic. Phylogenetic analysis based on sequence comparison of the conserved marker gene rpoA reveals that L. buchneri CD034 is more closely related to Lactobacillus hilgardii strains than to Lactobacillus brevis and Lactobacillus plantarum strains. Comparison of the L. buchneri CD034 core genome to other fully sequenced and closely related members of the genus Lactobacillus disclosed a high degree of conservation between L. buchneri CD034 and the recently sequenced L. buchneri strain NRRL B-30929 and a more distant relationship to L. buchneri ATCC 11577 and L. brevis ssp. gravesensis ATCC 27305, which cluster together with L. hilgardii type strain ATCC 8290. L. buchneri CD034 genome information will certainly provide the basis for further postgenome studies with the objective to optimize application of the strain in silage production.

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.

Effect of applying bacterial inoculants containing different types of bacteria to corn silage on the performance of dairy cattle

This study examined the effect of applying different bacterial inoculants to corn silage at the time of ensiling on the performance of lactating dairy cows. Corn plants were harvested at 35% dry matter (DM), chopped, and ensiled in 2.4-m-wide bags after application of (1) no inoculant (CON); (2) Biotal Plus II (B2) containing Pediococcus pentosaceus and Propionibacteria freudenreichii; (3) Buchneri 40788 (BUC) containing Lactobacillus buchneri; or (4) Buchneri 500 (B500) containing Pediococcus pentosaceus and L. buchneri. All inoculants were supplied by Lallemand Animal Nutrition (Milwaukee, WI). Each of the 4 silages was included in separate total mixed rations consisting of 44% corn silage, 50% concentrate, and 6% alfalfa hay (DM basis). Fifty-two lactating Holstein cows were stratified according to milk production and parity and randomly assigned at 22 d in milk to the 4 dietary treatments. Cows were fed for ad libitum consumption and milked twice daily for 49 d. Dietary treatment did not affect intakes (kg/d) of DM (20.0), crude protein (CP; 3.7), neutral detergent fiber (NDF; 5.7), or acid detergent fiber (ADF; 3.6), or digestibility (%) of DM (73.9) or CP (72.4). However, NDF digestibility was lower in cows fed B2 compared with those fed other diets (45.3 vs. 53.0%). Consequently, cows fed B2 had lower digestible NDF intake (kg/d) than those fed other diets (2.5 vs. 3.0 kg/d). Dietary treatment did not affect milk yield (32.3 kg/d), efficiency of milk production (1.61), concentrations of milk fat (3.18%) and protein (2.79%), or yields of milk fat (1.03 kg/d) and protein (1.26 kg/d). Inoculant application to corn silage did not affect milk yield or feed intake of cows.

Metabolic effects of feeding ethanol or propanol to postpartum transition Holstein cows

Eight lactating Holstein cows implanted with a ruminal cannula and permanent indwelling catheters in major splanchnic blood vessels were used to investigate metabolism of propanol and ethanol in the postpartum transition period. Cows were randomly allocated to 1 of 4 treatments in a randomized design with a 2 by 2 factorial arrangement of treatments. Factor 1 was 2.6g of calcium carbonate/kg of dry matter (DM) versus 1.5 g of 2-hydroxy-4-(methylthio)-butanoic acid isopropyl ester/kg of DM. Factor 2 was supplementation with 14 g of propanol/kg of DM (propanol treatment; PT) versus 14 g of ethanol/kg of DM (ethanol treatment; ET). Only factor 2 data are presented in the present paper. Treatments were administered in silage-based total mixed rations and cows were fed the experimental total mixed ration from the day of parturition. Daily rations were fed in 3 equally sized portions at 8-h intervals. Eight hourly sets of ruminal fluid, arterial, and hepatic portal and hepatic vein samples were collected at day -15 ± 5, 4, 15, and 29 relative to parturition. Dry matter intake and milk yield increased with days in milk (DIM), but were not affected by treatment. From prepartum to 4 DIM ruminal concentrations of propanol and ethanol increased with PT and ET, respectively. Postpartum, alcohol intake increased 49% in PT and 34% in ET from 4 to 29 d in milk, respectively. Ruminal concentrations of the alcohols remained unaffected by DIM. Treatments did not affect total ruminal volatile fatty acid concentrations, but the molar proportion of acetate increased in ET and the molar proportion of propionate increased in PT compared with the contrasting treatment. Propanol treatment decreased milk fat content at 15 to 29 DIM compared with ET. The net portal release of propanol and ethanol increased with increasing ruminal concentration of the respective alcohol. The portal release of alcohol accounted for 43 to 85% of ingested propanol and 36 to 57% of ingested ethanol. Hepatic uptake of propanol and ethanol equaled the net portal flux and no effect of treatment was detected for net splanchnic release of propanol and ethanol. In conclusion, ruminal metabolism is a major component of alcohol metabolism in dairy cows. The postpartum transition dairy cow has sufficient metabolic capacity to cope with high dietary concentrations of primary alcohols even when alcohol intake is abruptly increased at the day of calving. Alcohol intake affects milk fat content and alcohol composition of silage might be important to improve predictions of milk composition.

Complete genome sequence of Lactobacillus buchneri NRRL B-30929, a novel strain from a commercial ethanol plant

Lactobacillus buchneri strain NRRL B-30929 was a contaminant obtained from a commercial ethanol fermentation. This facultative anaerobe is unique because of its rapid growth on xylose and simultaneous fermentation of xylose and glucose. The strain utilizes a broad range of carbohydrate substrates and possesses a high tolerance to ethanol and other stresses, making it an attractive candidate for bioconversion of biomass substrates to various bioproducts. The genome sequence of NRRL B-30929 will provide insight into the unique properties of this lactic acid bacterium.

Effect of applying inoculants with heterolactic or homolactic and heterolactic bacteria on the fermentation and quality of corn silage

This study examined the effect of applying different bacterial inoculants on the fermentation and quality of corn silage. Corn plants were harvested at 35% DM, chopped, and ensiled in 20-L mini silos after application of (1) deionized water (CON) or inoculants containing (2) 1 × 10(5) cfu/g of Pediococcus pentosaceus 12455 and Propionibacteria freudenreichii (B2); (3) 4 × 10(5) cfu/g of Lactobacillus buchneri 40788 (BUC); or (4) 1 × 10(5) cfu/g of Pediococcus pentosaceus 12455 and 4 × 10(5) cfu/g of L. buchneri 40788 (B500). Four replicates of each treatment were weighed into polyethylene bags within 20-L mini silos. Silos were stored for 575 d at ambient temperature (25°C) in a covered barn. After silos were opened, aerobic stability, chemical composition, and yeast and mold counts were determined. The DNA in treated and untreated silages was extracted using lysozyme/sodium dodecyl sulfate lysis and phenol/chloroform and used as a template for a conventional PCR with primers designed on the 16S rRNA gene to detect the presence of L. buchneri in all silage samples. Acetic acid concentration was greater in B2 silages versus others (6.46 vs. 4.23% DM). Silages treated with BUC and B500 had lower pH and propionic acid concentration and greater lactic acid concentration than others. The B500 silage had the greatest lactic:acetic acid ratio (1.54 vs. 0.41), and only treatment with BUC reduced DM losses (5.0 vs. 14.3%). Yeast and mold counts were less than the threshold (10(5)) typically associated with silage spoilage and did not differ among treatments. Consequently, all silages were very stable (>250 h). Aerobic stability was not improved by any inoculant but was lower in B500 silages versus others (276 vs. 386 h). The conventional PCR confirmed the presence of similar populations of L. buchneri in all silages. This may have contributed to the prolonged aerobic stability of all silages.

Lactobacillus buchneri strain NRRL B-30929 converts a concentrated mixture of xylose and glucose into ethanol and other products

Lactobacillus buchneri strain NRRL B-30929 was isolated from a fuel ethanol production facility. This heterofermentative, facultative anaerobe can utilize xylose as a sole carbon source and tolerates up to 12% ethanol. Carbohydrate utilization (API, Biomerieux) and Phenotype Microarrays (PM, Biolog) analyses indicated that the strain is able to metabolize a broad spectrum of carbon sources including various monosaccharides (C5 and C6), disaccharides and oligosaccharides, with better rates under anaerobic conditions. In pH-controlled bioreactors, the bacterium consumed xylose and glucose simultaneously at high concentrations (125 g L(-1), pH 6.0). The major fermentation products were lactate (52 g L(-1)), acetate (26 g L(-1)) and ethanol (12 g L(-1)). The strain ferments glucose alone (pH 4.0) into lactate and ethanol with a molar ratio of 1.03:1. This strain will be further explored via genetic engineering for potential applications in biomass conversion.

Biogenic amine production in grass, maize and total mixed ration silages inoculated with Lactobacillus casei or Lactobacillus buchneri

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.

The effect of Lactobacillus buchneri on the fermentation, aerobic stability and ruminal degradability of maize silage

AIMS

To evaluate the effect of Lactobacillus buchneri, heterofermentative lactic acid bacteria (LAB), on the fermentation, aerobic stability and ruminal degradability of whole-crop maize silages under laboratory conditions. Two homofermentative LAB were tested for the purpose of comparison.

METHODS AND RESULTS

Maize was harvested at early dent [290 g kg(-1) dry matter (DM)] and one-half milk line (355 g kg(-1) DM) stages. Both homofermentative LAB were applied at 1 x 10(5) CFU g(-1) of fresh forage. Lactobacillus buchneri was applied at 1 x 10(5), 5 x 10(5) and 1 x 10(6) CFU g(-1) of fresh forage. Silages with no additives served as control. After treatment, the chopped forages were ensiled in 1.5-l anaerobic jars. Three jars per treatment were sampled on day 60. After 60 days of storage, silages were subjected to an aerobic stability test lasting for 5 days, in which CO(2) production, as well as chemical and microbiological parameters, was measured to determine the extent of aerobic deterioration. Both homofermentative LAB increased the concentration of lactic acid and the numbers of yeasts, and decreased the concentration of acetic acid and impaired the aerobic stability of silages. In contrast, applying L. buchneri decreased the concentration of lactic acid and increased the concentration of acetic acid of the silages. Under aerobic conditions, silages treated with 5 x 10(5) and 1 x 10(6) CFU g(-1) of L. buchneri, had lower pH, CO(2) production and the numbers of yeasts than the silages treated with 1 x 10(5) CFU g(-1) of L. buchneri (P < 0.05). However, all doses of L. buchneri and both homofermentative LAB did not affect in situ rumen DM, organic matter and neutral detergent fibre degradability of the silages.

CONCLUSIONS

Lactobacillus buchneri was very effective in protecting maize silages exposed to air under laboratory conditions. All doses of L. buchneri, especially 5 x 10(5) CFU g(-1) or more, markedly decreased the numbers of yeasts and improved the aerobic stability of silages.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of L. buchneri, as a silage inoculant, can improve the aerobic stability of maize silages by inhibition of yeast activity.

The Effects of Lactobacillus buchneri 40788 and Pediococcus pentosaceus R1094 on the Fermentation of Corn Silage

The effect of inoculating whole-plant corn at the time of harvest with Lactobacillus buchneri 40788 (4 x 10(5) cfu/g of fresh forage) combined with Pediococcus pentosaceus R1094 (1 x 10(5) cfu/g) on the fermentation and aerobic stability of corn silage (37% dry matter) through 361 d of ensiling was investigated. Dry matter recovery was similar between treatments throughout the study except at one early time point (14 d), when treated silage had a lower recovery than untreated silage. The concentration of lactic acid was unaffected by inoculation but inoculated silages had greater concentrations of 1,2-propanediol and acetic acid from 56 to 361 d of storage. In general, inoculation decreased the concentration of water-soluble carbohydrates but increased the concentration of ethanol. The numbers of yeasts was lower in inoculated silage at 42, 56, 70, and 282 d of ensiling. However, inoculation did not consistently improve the aerobic stability of silage, suggesting that microbes other than yeasts may have been responsible for aerobic instability in this study. Even after prolonged storage (361 d), silage treated with L. buchneri 40788 and P. pentosaceus R1094 had normal silage fermentation characteristics.

A Meta-Analysis of the Effects of Lactobacillus buchneri on the Fermentation and Aerobic Stability of Corn and Grass and Small-Grain Silages

The results of adding Lactobacillus buchneri to silages from 43 experiments in 23 sources reporting standard errors were summarized using meta-analysis. The effects of inoculation were summarized by type of crop (corn or grass and small grains) and the treatments were classified into the following categories: 1) untreated silage with nothing applied (LB0), 2) silage treated with L. buchneri at < or = 100,000 cfu/g of fresh forage (LB1), and 3) silage treated with L. buchneri at > 100,000 cfu/g (LB2). In both types of crops, inoculation with L. buchneri decreased concentrations of lactic acid, and this response was dose-dependent in corn but not in grass and small-grain silages. Treatment with L. buchneri markedly increased the concentrations of acetic acid in both crops in a dose-dependent manner. The numbers of yeasts were lower in silages treated with LB1 and further decreased in silages treated with LB2 compared with untreated silages. Untreated corn silage spoiled after 25 h of exposure to air but corn silage treated with LB1 did not spoil until 35 h, and this stability was further enhanced to 503 h with LB2. In grass and small-grain silages, yeasts were nearly undetectable; however, inoculation improved aerobic stability in a dose-dependent manner (206, 226, and 245 h for LB0, LB1, and LB2, respectively). The recovery of DM after ensiling was lower for LB2 (94.5%) when compared with LB0 (95.5%) in corn silage and was lower for both LB1 (94.8%) and LB2 (95.3%) when compared with LB0 (96.6%) in grass and small-grain silages.

The Effects of Various Antifungal Additives on the Fermentation and Aerobic Stability of Corn Silage

In 2 consecutive years, whole plant corn was ensiled in laboratory silos to investigate the effects of various silage additives on fermentation, dry matter (DM) recovery and aerobic stability. In yr 1, chopped forage was treated with 1) no additive (untreated, U), 2) Lactobacillus buchneri 40788, 4 x 10(5) cfu/g of fresh forage (LLB4), 3) L. buchneri 11A44, 1 x 10(5) cfu/g (PLB), 4) Biomax 5 (Lactobacillus plantarum PA-28 and K-270), 1 x 10(5) cfu/g (B5), 5) Silo Guard II (sodium metabisulfite and amylase), 0.05% of fresh forage weight (SG), 6) a buffered propionic acid-based additive, 0.1% (Ki-112), 7), sodium benzoate, 0.1% of fresh weight (SB), or 8) potassium sorbate:EDTA (1:1), 0.1% of fresh weight (PSE). Silage treated with LLB4 had the highest concentration of acetic acid compared with other treatments, and yeasts were undetectable in LLB4 (<log2 cfu/g). Silages treated with SB and PSE had the highest concentrations of water-soluble carbohydrates, the greatest recoveries of DM, and the lowest concentrations of ethanol. Silages treated with B5, SG, and Ki-112 had no effects on fermentation, DM recovery, or aerobic stability. The aerobic stabilities of silages treated with LLB4, SB, and PSE were greatest among all treatments. In yr 2, treatments were: 1) U, 2) LLB4, 3) PLB, 4) PLB at 4 x 10(5) cfu/g (PLB4), and 5) B5. Silages treated with L. buchneri had greater concentrations of acetic acid but lower concentrations of ethanol than did U- and B5-treated silages. Yeasts were undetected in all silages except in silage treated with B5, which had the poorest aerobic stability of all treatments. Treatments had no effect on DM recovery. Silages treated with PLB, PLB4, and LLB4 remained stable for >210 h.

Microbial counts, fermentation products, and aerobic stability of whole crop corn and a total mixed ration ensiled with and without inoculation of Lactobacillus casei or Lactobacillus buchneri

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.

The Effects of Buffered Propionic Acid-Based Additives Alone or Combined with Microbial Inoculation on the Fermentation of High Moisture Corn and Whole-Crop Barley

Buffered propionic acid-based additives (BP) alone or in combination with a microbial inoculant containing lactic acid bacteria (MI) were mixed with ground, high moisture corn or whole-crop barley and ensiled in triplicate laboratory silos to investigate their effects on silage fermentation and aerobic stability. The inoculant and chemicals were applied separately for treatments that included both additives. The addition of MI alone had no effect on DM recovery, fermentation end products, or aerobic stability of high moisture corn. However, treatments with 0.1 and 0.2% BP (alone and the combination) had more than 10- and 100-fold fewer yeasts, respectively, and they also had greater concentrations of propionic acid than did untreated corn. Corn treated with only 0.1 (161 h) and 0.2% (218 h) BP tended to be more stable when exposed to air than untreated corn (122 h). Treatment with MI + 0.2% BP markedly improved the aerobic stability (>400 h) of high moisture corn. With whole-crop barley, the addition of MI alone, BP alone, and combinations of MI and BP prevented the production of butyric acid that was found in untreated silage (0.48%). All barley silages that had MI in their treatments underwent a more efficient fermentation than treatments without MI, as evident by a greater ratio of lactic:acetic acid and more DM recovery than in untreated silage. Increasing levels (0.1 to 0.2%) of BP added together with MI improved the aerobic stability of barley (190 and 429 h) over the addition of MI alone (50 h). These data show that buffered propionic acid-based products are compatible with microbial inoculants and, in some circumstances when used together, they can improve the fermentation and aerobic stability of silages.