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 × 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 (>106 CFU g−1) or L. buchneri (>106 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 104, 105 and 106 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 105 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.

Wet brewers grains were stored as a total mixed ration (TMR) in laboratory silos with lucerne hay, cracked maize, sugar beet pulp, soya bean meal and molasses at 5:1:1:1:1:1 on fresh weight basis. The TMR mixture was inoculated with or without Lactobacillus casei or Lactobacillus buchneri to obtain silages with differing fermentation and stability after exposure to air. In the first experiment, ensiling was stopped at 10, 20 and 60 days, and the stability was tested for the following 7 days. Ethanol and lactic acid were the main products in untreated TMR silage, while addition of L. casei and L. buchneri increased lactic and acetic acid, respectively. No silages deteriorated in the presence of air over 7 days, regardless of inoculation, ensiling period and the level of yeasts determined at unloading. In the second experiment, silos were opened at 14 days and then subjected to aerobic stability test for 14 days. Resistance to deterioration was sustained in the untreated control, even with a high population (>10 4 cfu g −1 ) of yeasts throughout the 14-day test. Spoilage was found in L. casei-treated silage at about 5 days, while increase of yeasts preceded the distinct heating (degradation). In L. buchneri-treated silage, no yeasts were detected at unloading or after exposure to air. These results suggest that substantial stability can be expected in TMR silage with or without inoculation of lactic acid bacteria. This property is not associated with the counts of yeasts at loading and the characteristics of silage such as alcoholic and lactic acid fermentation.