Impact of hexamine addition to a nitrite-based additive on fermentation quality, Clostridia and Saccharomyces cerevisiae in a white lupin-wheat silage

BACKGROUND Nitrite and hexamine are used as silage additives because of their adverse effects on Clostridia and Clostridia spores. The effect of sodium nitrite and sodium nitrite/hexamine mixtures on silage quality was investigated. A white lupin-wheat mixture was treated with sodium nitrite (NaHe0) (900 g t(-1) forage), or mixtures of sodium nitrite (900 g t(-1)) and hexamine. The application rate of hexamine was 300 g t(-1) (NaHe300) or 600 g t(-1) (NaHe600). Additional treatments were the untreated control (Con), and formic acid (FA) applied at a rate of 4 L t(-1) (1000 g kg(-1)). RESULTS Additives improved silage quality noticeably only by reducing silage ammonia content compared with the control. The addition of hexamine to a sodium nitrite solution did not improve silage quality compared with the solution containing sodium nitrite alone. The increasing addition of hexamine resulted in linearly rising pH values (P <0.001) and decreasing amounts of lactic acid (P <0.01). Sodium nitrite based additives were more effective than formic acid in preventing butyric acid formation. Additives did not restrict the growth of Saccharomyces cerevisiae compared to the control. CONCLUSION The addition of hexamine did not improve silage quality compared with a solution of sodium nitrite. (c) 2018 Society of Chemical IndustryPeer reviewe

Valkolupiinin soveltuvuus säilörehuksi

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The European race of Gremmeniella abietina hosts a single species of Gammapartitivirus showing a global distribution and possible recombinant events in its history

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The effect of additives on the quality of white lupin–wheat silage assessed by fermentation pattern and qPCR quantification of clostridia

The efficacy of different silage additives on different mixtures of white lupin and spring wheat was investigated in four separate trials. The bicrop was harvested 96 days (trials 1 and 2) and 110 days (trials 3 and 4) after sowing. For each maturity stage, two mixtures of white lupin and spring wheat were reformed in the ratios of 1:2 and 2:1 on fresh matter (FM) basis respectively. The crops were treated with formic acid (FA), sodium nitrite–hexamine mixture (NaHe) or homofermentative lactic acid bacteria (LAB). The control silage was made without additive. Additives were not able to improve the quality of white lupin–wheat silage in all trials, compared with untreated silage. The treatment with LAB showed good results only at the first stage of crop maturity with sufficient amounts of water-soluble carbohydrate in the pre-ensiling crops. The FA treatment showed elevated butyric acid levels in all trials, which suggests that the FA application level used (4 L t 1 FM, 100% FA) was insufficient to decrease pH enough for preventing the growth of clostridia and butyric acid fermentation. NaHe was the only additive that was able to inhibit the activity of clostridia in all trials.201