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Silage Grass & Alfalfa

Grass silage: why using inoculants?

Grass silage: why using inoculants?

Like wine or cheese, ensiling is a 1,000-year-old preservation technique based on fermentation, thus a natural process, relying on the action of acidifying bacteria found on the plants surface. But sometimes, nature needs a little help to make sure things go well and the fermentation process is optimal. The addition at harvest of selected naturally occurring bacteria, or silage inoculants, in sufficient quantity to ensure optimal fermentation, even when conditions are not ideal, can help (this is also true for cheese and wine!). This is especially true in the case of grass for several reasons:

  • Grass is poor in sugar: sugar is the starting element of lactic acid fermentation, which makes grass a crop difficult to ensile. Consequently, fermentation kinetic is slow, leaving more room for bad fermentations to occur, leading to spoilage.
    • Silage inoculant containing specific lactic acid bacteria and enzymes to break down complex sugars help kick-start the fermentation process.
  • Not everything can be controlled: climate technical issues … you cannot predict bumps in the road at harvest or when ensiling.
    • The use of silage inoculant is an insurance against uneven conditions.
  • However good the silage management practices are, dry matter losses occur all along the process, from the field to the trough. Indeed, the average DM loss, from field to feedout for grass silage, is about 23.6% (Buckmaster, Rotz and Black).
    • Inoculants minimize nutrient loss at every step:
      • Quicker initial fermentation prevents spoilage during ensiling.
      • All along the fermentation process thanks to the selection of bacteria that are active at different pH levels.
      • At feedout: first of all, adequate feedout rate is essential to ensure minimal DM loss through heating and secondary fermentations. However, well-preserved, well-packed silage will keep fresh for longer. Moreover, the use of “gate keeper bacteria”, such as Propionibacteria acidipropionici help fight against spoilage bacteria and reduces heating at feedout – protecting more DM and nutrients content at feedout.

The use of adapted grass silage inoculant can help preserve forage value and farm profitability at every step of the process!