A note on ensiling safflower forage

Abstract The ensiling characteristics of safflower ( Carthamus tinctorius ) wilted to 290 and 411 g dry matter (DM) kg⁻¹ fresh material were studied in 1·5 l glass jars. The experiment included a control and the application of Lactobacillus plantarum at 3·3 × 10⁵ colony-forming units (cfu) per g of crop. After 60 days of ensiling, the pH of safflower silages was 4·6 and 4·0 in the control and inoculated silages respectively, with corresponding values for lactic acid, the major fermentation product, of 20 and 45 g kg⁻¹ DM. The silages from the anaerobic jars were stable upon aerobic exposure. It is concluded the safflower silage has potential as an alternative fodder in semiarid regions.     

Determination of microbial protein in perennial ryegrass silage

The microbial matter fraction was determined in perennial ryegrass silages of different dry-matter (DM) contents, ensiled with or without Lactobacillus plantarum . ¹⁵N-Leucine and the bacterial cell wall constituent diaminopimelic acid (DAPA) were used as markers for microbial-N. Perennial ryegrass crops with DM contents of 202, 280 or 366 g kg⁻¹ fresh weight were ensiled in laboratory-scale silos and stored for 3 to 4 months. At different times after ensiling, silages were analysed and microbial fractions were isolated. Microbial-N concentration determined with ¹⁵N-leucine reached a maximum during the first week of ensilage. It remained unchanged thereafter, except in silage with a DM content of 280 g kg⁻¹ in which it decreased ( P  < 0·01) by 32% during storage. After 3 to 4 months ensilage, microbial-N concentration varied from ≈0·3 to ≈1·7 g kg⁻¹ DM. A negative relationship was observed between microbial-N concentration and silage DM content. Inoculation resulted in an approximately twofold increase ( P  < 0·001) in microbial-N concentration. Microbial-N concentrations determined with DAPA were 1·14–2·07 times higher than those determined with ¹⁵N-leucine. However, 19–35% of the DAPA in silage occurred in a soluble form, indicating that this fraction of DAPA was not associated with intact bacteria.     

RESEARCH NOTE

Data from twenty-two experiments conducted at tour ADAS Research Centres during 1980–92 were used to compare untreated silages with silages treated with formic acid, with or without added formalin, commercial inoculants or molasses. The sillages were made from herbage whose dry-matter (DM) and water-soluble carbohydrate (WSC) contents were 277 (s.e. 0.46) g DM kg⁻¹ and 36 (s.e. 8.1) g kg⁻¹ respectively. Inoculant use significantly decreased silage pH and ammonia-N, significantly increased lactic acid and total acid content, and decreased butyric acid and total short-chain fatty acids. Formic acid use significantly increased silage lactic acid and total acid content, and decreased butyric acid content, whereas formic acid+formalin significantly decreased silage ammonia-N level. Molasses had little effect upon silage fermentation. Improvements in silage fermentation, however, produced little benefit in terms of either silage DM intake or liveweight gain when the silages were offered to growing lambs.
It is suggested from the results that inoculant- and formic acid-based additives can be used to improve the fermentation of big-bale silages.     

Aerobic stability of sugar-cane silage inoculated with tropical strains of lactic acid bacteria

Aerobic stability is an important feature in the evaluation of silages. The aims were to investigate the chemical and microbiological changes that occur in sugar-cane (Saccharum spp.) silage after aerobic exposure, to identify the major species of yeasts associated with the aerobic deterioration process and to select lactic acid bacteria (LAB) strains that can improve the aerobic stability of this silage. Fourteen wild LAB strains belonging to Lactobacillus plantarum, L. brevis and L. hilgardii were evaluated using experimental silos. Silage samples were collected at 0, 96 and 216 h after aerobic exposure to determinate the DM, WSC, pH, products of fermentation, to evaluate the silage temperatures and to identify yeast species associated with the aerobic deterioration of silage. The strains tested were able to modify the fermentative and chemical parameters and the diversity of yeasts species of silage after aerobic exposure. There was no association between the facultative or obligatory heterofermentative fermentation patterns and the increased aerobic stability of silage. Aerobic stability of sugar-cane silages was associated with high acetic acid and 1,2-propanediol concentrations. L. hilgardii UFLA SIL51 and UFLA SIL52 strains promoted an increase in aerobic stability of silage.     

Effects of Lactobacillus buchneri isolated from tropical maize silage on fermentation and aerobic stability of maize and sugarcane silages

This study was aimed to perform a screening of Lactobacillus buchneri strains from maize silage and use them as inoculant in maize and sugarcane silages. In all, 151 lactic acid bacteria (LAB) strains were isolated from whole‐plant maize silage, and their identification was based on the sequence analysis of 16S rDNA. In total, 15 strains were categorized to the L. buchneri group and eight of these were selected based on growth rate and fermentation pattern. The selected strains were evaluated on fermentation and aerobic stability of maize and sugarcane silages. For maize, the inoculated silages had lower pH and higher LAB population, but lower acetic acid concentration in comparison with the untreated control silage. For sugarcane silage, the strains 56.1, 56.4 and 40788 resulted in highest dry‐matter (DM) content and lowest DM losses. However, only the strain 40788 showed lowest counts of yeasts and moulds. Sugarcane silages inoculated with the strains 56.9, 56.26 and the untreated control silage showed highest concentrations of lactic acid and ethanol, besides the great DM losses. Even so, for both crops, the aerobic stability was not affected by inoculation. After air exposure, all silages increased temperature and had high population of yeast and moulds. Nevertheless, the strains 56.1 and 56.4 are promising for use as a silage inoculant.     

Silage and milk production: studies with diets containing white clover silage

In three separate feeding experiments using a total of twenty-six individually-housed Ayrshire cows, three wilted silages made from Blanca white clover were offered ad libitum with either different supplements or different proportions of grass silage. The clover silages contained 680 g white clover kg⁻¹ on a DM basis, and had a mean DM concentration of 263 g kg⁻¹ with 231 g CP kg⁻¹ DM and 91 g ammonia-N kg⁻¹ N. The pH values averaged 4·16 and the DOMD concentrations 611 g kg⁻¹. In experiment 1 the daily intake of clover silage given alone was 15.2 kg DM per cow, i.e. 30·1 g kg⁻¹ live weight, and decreased by 0·76 kg DM kg⁻¹ barley DM and by 0·66 kg DM kg⁻¹barley plus soybean meal DM when these feeds were offered as supplements. Milk yield and fat concentration were higher on the supplement treatments than on the clover silage-only treatment. In experiments 2 and 3 the intakes of silage and total DM increased as the weight of clover in the diet increased from 0 to 700 g kg⁻¹ with parallel increases in milk yield. The effects on milk composition were small and generally non-significant. Although white clover silages with excellent fermentations were made, it is concluded that the main role of white clover in a silage system will be in mixed swards with grass to reduce the input of fertilizer N and to increase the voluntary intake of silage.     

Effects of inoculants and wilting on silage fermentation and nutritive characteristics of red clover–grass mixtures

Various management practices (e.g. wilting, application of silage additives or adding a grass component) can be used to improve silage fermentation of pure red clover (Trifolium pratense L.). Therefore, the aim of this laboratory ensiling study was to investigate the effects of varying proportions of red clover and perennial ryegrass (100/0, 66/33, 33/66, 0/100) on silage quality during two consecutive years. In addition, two wilting levels [target dry matter (DM): 300 vs. 400 g kg^?1] in combination with lactic acid bacteria (LAB) additives were tested. Herbage was ensiled, either untreated or inoculated with homofermentative LAB (low wilted) or homo‐ and heterofermentative LAB (high wilted). In most cases, lactic and acetic acid decreased as the proportions of ryegrass were increased. Data concerning ammonia‐N concentrations showed considerable differences between cuts and years. Silages treated with homofermentative LAB generally had high lactic acid and low final pH, whereas acetic acid and 1,2‐propanediol tended to be higher when homo‐ and heterofermentative LAB were applied. Inoculants had a positive effect on DM losses and ammonia‐N in only a few silages. Wilting decreased DM losses and fermentation acids at most cuts, irrespective of the grass/clover ratio in the herbage mixture. There was a strong year effect on the organic matter digestibility (DOM) of the silages. In conclusion, the optimal strategy for successful silage fermentation of red clover is the ensiling in mixtures with ryegrass. Furthermore, herbage should be wilted to a DM content of about 300–350 g kg^?1. The application of LAB inoculants did not alter the DOM but did improve silage fermentation.     

Effect of stage of maturity of whole-crop barley on intake and liveweight gain by dairy steers differing in initial live weight

The effect of maturity at harvest of whole-crop barley for ensiling on intake and liveweight gain of dairy steers differing in initial live weight (LW) was evaluated in an experiment over two years. Light (104–120 kg) and heavy (402–419 kg) dairy steers were fed diets containing predominantly whole-crop barley silage harvested at the milk stage [dry matter (DM) content of 284 g kg⁻¹ and neutral-detergent fibre (NDF) concentration of 526 g kg⁻¹ DM] or the dough stage of maturity (DM content of 328 g kg⁻¹ and NDF concentration of 445 g kg⁻¹ DM) and supplemented with up to 1 kg of concentrate. Dry matter intake (g kg⁻¹ LW) was higher for whole-crop barley harvested at the dough stage than at the milk stage of maturity and the difference was greater in heavy than in light steers ( P <  0·001). Liveweight gain was higher and feed conversion ratio was lower for dough-stage compared with milk-stage silage ( P  <   0·05) but there was no interaction with size of steer. Whole-crop barley harvested at the dough stage of maturity promoted higher liveweight gains in dairy steers compared with whole-crop barley harvested at the milk stage due to a higher DM intake.     

Effects of ethanol,molasses and Lactobacillus plantarum on fermentation characteristics and aerobic stability of total mixed ration silages

This study was conducted to evaluate the effects of Lactobacillus plantarum, molasses and/or ethanol on fermentation quality and aerobic stability of total mixed ration (TMR) silage, which is widely used in dairy cow diets at mid‐to‐late lactation in Tibet. TMR was treated with ethanol (E), molasses (M), Lactobacillus plantarum(L), ethanol+molasses (EM), ethanol+Lactobacillus plantarum (EL) plus control. After 45 d of ensiling, inoculant significantly (P < 0·05) increased lactic acid (LA) concentration and decreased pH, ammonia nitrogen (AN) concentration, and aerobic bacterial and yeast counts, compared to control. After the first 3 d of aerobic exposure, LA for silages without ethanol started to decrease, while LA for E silages almost remained unchanged till the end of the aerobic exposure period. The pH in TMR silages without ethanol gradually increased, while that for E and EL remained about 4·60 and 4·00, respectively, and EL showed the lowest pH among six silages over the course of aerobic exposure. Aerobic bacterial counts in control, M and EM silages were significantly higher (P < 0·05) than those in E, L and EL, and yeast counts in E and EL silages were significantly lower (P < 0·05) than those in other silages after 9 d of aerobic exposure. The results suggest that inoculation with L. plantarum was more effective in altering fermentation characteristics than adding molasses, while ethanol showed a potential to protect TMR silages from pH increase and delayed the growth of aerobic bacteria and yeast either alone or in combination with L. plantarum.     

Enzymes as silage additives for grass–clover mixtures

Seven laboratory-scale experiments were carried out to study the effects of cellulases/hemicellulases on silage fermentation of herbage from mixed swards of timothy ( Phleum pratense ), meadow fescue ( Festuca pratensis ) and red clover ( Trifolium pretense ). Enzyme-treated silage (approximately 3500 HEC units kg⁻¹ grass) reached a low pH sooner, had lower end pH, contained less NH₃-N and more lactic acid than did the untreated silage ( P < 0·05). Applied with an inoculant, these effects were even stronger. With easily ensiled crops (experiments 1, 2, 5 and 6) preservation was first of all improved by inoculation of lactic acid bacteria; however, for the low-sugar crops (experiments 3, 4 and 7) enzyme treatment was more significant. The enzymes derived from Aspergillus spp. gave more acetic acid than the enzymes from Trichoderma reesei. The Trichoderma enzymes liberated 4·8 g WSC kg⁻¹ FM gamma-irradiated grass during 60 d at pH 4·3 ( P < 0·05). On average, for all silages enzyme treatment increased the sum of residual sugar and fermentation products by 3·7 g kg⁻¹ FM (21 g kg⁻¹ DM) compared with the silages not treated with enzymes ( P < 0·001). Enzyme treatment increased the instantly degradable part of the feed, but total in sacco and in vitro digestibilities were not affected.     

Re‐ensiling and inoculant application with Lactobacillus plantarum and Propionibacterium acidipropionici on sorghum silages

Re‐ensiling of previously ensiled forage has been a common practice in Brazil, and the use of inoculants may provide a means of reducing dry‐matter (DM) loss. This study aimed to determine the effect of re‐ensiling and the use of microbial inoculants on the quality of sorghum silage. Treatments were presence/absence of an inoculant (Lactobacillus plantarum and Propionibacterium acidipropionici) in the silage, and the re‐ensiling, or not, of the material after 24 h of exposure to air, and these were tested in a factorial 2 × 2 design. Losses due to gas, effluent and total DM were assessed, as were the fermentation characteristics, chemical composition, aerobic stability, and aerobic counts of microorganisms. Effluent loss was higher in re‐ensiled silage, and these silages had lower lactic acid content and higher levels of acetic and propionic acids. The in vitro DM digestibility was lower in the re‐ensiled sorghum silages. The re‐ensiled silage had higher aerobic stability. The inoculant only increased the acetic acid content of the silage. The re‐ensiling of sorghum silage increased effluent loss by 71·2%, and reduced DM digestibility by 5·35%. The use of inoculant did not influence the quality of sorghum silage.     

Effects of potassium sorbate and sodium benzoate at two application rates on fermentation and aerobic stability of maize silage

This study evaluated two potassium sorbate (PS) and sodium benzoate (SB) application rates in improving the aerobic stability of maize silage. Treatments included no additive, the addition of PS at 1 and 2 g kg^?1 fresh matter (FM) and the addition of SB at 1 and 2 g kg^?1 FM. Four replicates of each treatment were ensiled in 15‐L plastic jars. The silages were analysed for their fermentative characteristics and were subjected to an aerobic stability test with pH and yeast and mould count measurements. Considering fermentation quality and aerobic stability, both additives were effective. The PS was more active against yeasts during aerobic exposure. When the additives were applied at 2 g kg^?1, the silages were more stable (256 h, on average) than those with 1 g kg^?1 (119 h, on average) and control (61 h). Aerobic deterioration was more pronounced in the controls than in the treated silages. Silages treated at 2 g kg^?1 had consistent effects on pH values and yeast counts over 288 h of aerobiosis. Overall, PS and SB applied at 2 g kg^?1 were more effective in improving aerobic stability.     

Fermentation and nutritive value of Zea mays and lucerne forage ensiled with added rolled barley

The effect of adding rolled barley on the ensiling characteristics and nutritive value of lucerne and corn ( Zea mays ) forage was studied using 19-1 plastic mini-silos. Other factors evaluated with lucerne were the effect of wilting and added lactic acid bacteria. Rolled barley was added at rates of 0, 50, 100 and 150gkg⁻¹ (wet weight) to lucerne or corn forage. Lucerne was ensiled at 170–330 g kg⁻¹ dry matter (DM) and lactic acid bacteria were applied at 10⁵g⁻¹ wet forage. Addition of rolled barley consistently improved the fermentation of lucerne by lowering the pH and decreasing the concentration of acetate and ammonia nitrogen. Wilting of lucerne had variable effects on fermentation in two experiments. The addition of lactic acid bacteria improved fermentation by decreasing the concentrations of acetate and ammonia nitrogen, improved the nutritive value by increasing the in vitro dry matter digestibility (IVDMD), and was associated with decreased amounts of lactic acid. Corn was ensiled at 250 g kg⁻¹ DM, and added rolled barley had little effect on the fermentation of corn silage. The digestibility of all silages determined in vitro was improved by the addition of rolled barley.     

The effect upon fermentation and nutritive value of silages produced after treatment by three different inoculants of lactic acid bacteria applied alone or in combination

Silages were made from the first cut of a predominantly perennial ryegrass sward. The silages were either untreated (W) or treated with formic acid (31 t⁻¹, F) or with 10⁶ lactic acid bacteria (LAB) g⁻¹ grass of each of three strains alone (A. Lactobacillus plantarum MTD1; B, Pediococcus species 6A2; C, L. plantarum 6A6) or in combination (AB. AC) to give seven treatments. The silage fermentation in 10-kg silos was followed chemically and microbiologically and the nutritive value of selected treatments evaluated using 2-t silos.
The control silage (W) fermented well. Addition of formic acid restricted fermentation and produced a silage with a high ethanol concentration. After day 4, all inoculated silages had lower pH values and higher lactic acid concentrations and a higher ratio of lactic acid to acetic acid than the control silage. Chemically there was little difference between the inoculated silages in terms of final composition. Microbiologically the LAB applied in treatments B and C dominated the LAB populations in those silages when applied alone; however, they were suppressed when applied in combination with inoculant A.
When fed to sheep, the intake of the formic acid-treated silage was significantly ( P < 0·01) lower than that of the other silages and the intake of silage treated with inoculant A significantly ( P < 0·001) higher than that of silages treated with inoculants B and C. The apparent organic matter ( P < 0·001) and nitrogen ( P < 0·01) digestibilities of the formic acid-treated silage were also significantly lower than those of the other silages.     

Effects of additives on the fermentation and aerobic stability of grass silages and total mixed rations

Mown herbage of timothy–meadow fescue (dry matter 218 (LDM) or 539 (HDM) g kg^?1) was ensiled in laboratory silos to evaluate silage additives. For LDM silage, additives including formic acid (a blend of formic acid, sodium formate, propionic acid, benzoic acid, glycerol and another blend of formic acid and ammonium formate, both applied at 5 L t^?1) were able to restrict fermentation and thereby improve intake potential of the silage. Aerobic stability (AS) of total mixed ration (TMR) was also improved. LDM grass treated with homofermentative lactic acid bacteria (_hoLAB) resulted in silage containing lactic acid at 132 g kg^?1 DM, ammonium‐N <40 g kg^?1 total N, and pH < 3·8, and the AS was poor (<36 h). The treatment including heterofermentative strain (Lactobacillus brevis) produced more acetic acid and better AS than _hoLAB. Salt treatment (sodium benzoate, potassium sorbate, sodium nitrite) reduced pH compared to the Control treatment (3·89 vs. 4·24) and improved AS of TMR. The LDM Control silage had good AS, but the TMR based on it had poor AS. All additives were able to lower pH on HDM silages also, but other benefits of using additives were minimal. The treatment including L. brevis on HDM was able to improve AS of TMR.     

Lactic acid bacteria strains for enhancing the fermentation quality and aerobic stability of Leymus chinensis silage

Leymus chinensis is an important grass in China and Russia. Six lactic acid bacteria (LAB) strains (LB, LPL1, LPL2, LPL3, LCL and WH) from L. chinensis silage were screened and identified and their effects on fermentation quality were investigated. All six strains were grown at 6·5% NaCl and pH 4·00. Strains LPL1, LPL2 and LPL3 were identified as Lactobacillus plantarum, and LB, WH and LCL were classified as Lactobacillus brevis, Weissella hellenica and Lactobacillus casei respectively. The six isolated strains and a commercial inoculant (Lactobacillus buchneri) were added to L. chinensis for ensiling at densities of 500 and 600 kg m^?3. The control was sprayed with the same volume of distilled water. The effects of the strains on fermentation quality after 45 d ensiling and aerobic stability during 8 d of exposure to air were evaluated. The 600 kg m^?3 silage had lower pH, butyric acid, ammonia nitrogen content and coliform bacteria counts than the 500 kg m^?3 density silage (P < 0·05). The six isolated strains decreased pH, butyric acid content and increased lactic acid content, and all inoculants increased L. chinensis silage aerobic stability except LCL (P < 0·05). The fermentation quality of L. chinensis silage increased with higher ensiling density. The LAB strains improved the fermentation quality, and high‐quality silage could be obtained at low ensiling density with the addition of the LAB strains. The strains improved the aerobic stability; Lb. buchneri and Lb. brevis showed the best performance.     

Silage and milk production: a comparison between unwilted and wilted grass silages

Three grass silages made in sunny weather in early July from second-harvest perennial ryegrass were compared in a 16-week feeding experiment with twelve Ayrshire cows. The silages were either unwilted or wilted with and without conditioning, and had mean dry matter (DM) concentrations of 201, 261 and 272 g kg⁻¹, and in vitro DOMD concentrations of 650, 669 and 672 g kg⁻¹ DM respectively. All the silages had formic acid ('Add-F') applied at a rate of 2.6 litres t⁻¹ and were offered ad libitum plus 6 kg concentrates per cow per d. The daily intakes of silage DM were 905 kg per cow on the unwilted treatment and 9.86 and 9.65 kg on the wilted treatments with and without conditioning respectively. Daily milk yields were 171, 17.6 and 17.4 kg per cow on the unwilted, and wilted with and without conditioning treatments respectively and were not significantly different. Fat concentrations in the milk were not affected significantly by treatment, whereas the crude protein and solids-not-fat concentrations were significantly higher on the wilted than on the unwilted treatment. The efficiency of utilization of metabolizable energy for lactation was 6–7% lower with the wilted than with the unwilted silages and it is concluded that the unwilted silage was superior to the wilted silages as a feed for dairy cows.     

Separating the effects of forage source and field microbiota on silage fermentation quality and aerobic stability

This study attempted to separate the effects of forage source and field microbiota on silage fermentation quality and aerobic stability. Single samples of grass, red clover and maize were used. Field microbiota was obtained by centrifugation of microbial suspensions of the three samples. The intact forages were dried and sterilized by heating at 60°C for 3 h + 103°C for 15 h, inoculated in a 3 (forage) × 3 (inoculum) design and reconstituted to a dry‐matter level of 400 g kg^?1 before ensiling. After ensiling for 71 d, subsamples were subjected to an 8‐d aerobic stability test, which included temperature and pH measurements. Bacterial community analysis was performed on samples before and after ensiling by 16S rRNA gene amplicon sequencing. Forage source had a marked effect on the levels of lactic acid, acetic acid, ammonia‐N and 2,3‐butanediol, but microbiota source only affected the acetic acid concentration. The forage and microbiota as well as their interactions affected silage stability variables. The maize microbiota improved silage stability, whereas silages made from the maize forage had the poorest stability. Bacterial community analysis revealed higher abundance of lactic acid bacteria on the maize forage, with Lactococcus and Leuconostoc being the dominant genera. These preliminary results suggested that fermentation quality is mainly affected by forage source, whereas the aerobic stability is affected by both forage and field microbiota.     

The effects of lactic acid bacteria on the fermentation,aerobic stability and nutritive value of maize silage

Maize was harvested at one‐third milk line (297 g kg^?1 DM) stage. All inoculants were applied at 1 × 10⁶ cfu g^?1 of fresh forage. After treatment, the chopped forages were ensiled in 1·5‐L anaerobic jars. Three jars per treatment were sampled on days 2, 4, 7, 12 and 90 after ensiling, for chemical and microbiological analysis. Homofermentative LAB‐inoculated silages had lower pH and higher lactate:acetate ratio (except for Lactobacillus plantarum/Pediococcus cerevisiae and L. plantarum/Propionibacterium acidipropionici) than the control and both heterofermentative LAB‐inoculated silages. Both L. buchneri inhibited yeast growth and CO₂ production during exposure of silage to air. The L. plantarum/P. cerevisiae, L. plantarum (Ecosyl) and L. plantarum/Enterococcus faecium‐inoculated silages had higher dry‐matter digestibility than the control and L. buchneri‐inoculated silages. Inoculants did not affect digestibility of neutral detergent fibre, except for L. buchneri (Biotal), organic matter nor ME content of silages. The LAB silage inoculants generally had a positive effect on maize silage characteristics in terms of lower pH and shifting fermentation toward lactate with homofermentative LAB or toward acetate with L. buchneri. The use of L. buchneri can improve the aerobic stability of maize silages by the inhibition of yeast activity.     

Influences of enterobacteria on the fermentation and aerobic stability of grass silages

Grass (220 g DM kg⁻¹ was ensiled after adding 10⁶ and 10⁸ enterobacteria (90% Rahnella aquatilis , 9·9% Hafnia alvei and 0·1% Escherichia coli g⁻¹ fresh mutter. The silages were exposed to aerobic conditions alter 125 d of storage. In all treatments H. alvei rapidly superseded the initial high number of Enterobacter agglomerans (naturally present) and R. aquatilis. The maximum number of enterobacteria was detected about I d after initiation of fermentation. After 4 d of fermentation, when concentrations of undissociated lactic and acetic acids ranged from 52 to 36 mM and 41 to 51 mM respectively, no enterobacteria were detectable. Inoculating the crop with enterobacteria restilted in a temporarily retarded rate of production of lactic and acetic acids and a 50% increase in the concentration of ammonia-N. The concentration of endotoxin in the silages was 6–7 μg g⁻¹ fresh matter. There was no change in the level of endotoxin during ensiling. High numbers of enterobacteria at the beginning of the fermentation improved the aerobic stability of the silages. There was a lag in the decrease in concentrations of acids and delays in the increase in pH, respiration rate and numbers of yeast and Bacillus spores, in uninoculated silages the pH increased from 4·1 to 5·0 after 8 d of aerobic storage, whereas in inoculated silages a pH of 5·0 was not reached until after 16 d of storage.