Feed intake: If silage smells of adhesive

Over the last few years there have been an increasing number of reports regarding unusual smells in silage. silage. . They are described as being unpleasantly pungent, musty, or like adhesive. The animals themselves react by refusing feed, provide less milk, and become ill.

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Formation of esters in silage should be prevented in advance by using BioCool silage agent to ensure feed intake.Feed intake: If silage smells of adhesive
Formation of esters in silage should be prevented in advance by using BioCool silage agent to ensure feed intake.

However, the substances responsible for this phenomenon in silage are now known. Lactic and acetic acid can react with ethanol to create ethyl esters (e.g. ethyl lactate, ethyl acetate) in anaerobic conditions. The smell of such substances are reminiscent of adhesive or nail polish remover. It cannot be explained with certainty why such reactions take place. Well-fermented silage with high levels of compression tend to be affected more frequently than poorer-quality silage.

Observe animals during feed intake

If this phenomenon occurs in silage, feed intake falls dramatically, even as far as complete refusal. In such cases it is recommended that affected silage is “ventilated” as these substances are volatile and will outgas. Practical experience also shows that using Vitamiral Bulle Relax in the total mixed ration (TMR) can be helpful. The recommended quantity ranges from 200 to 250 grams per animal, per day. Vitamiral Bulle Relax buffers these acids, improves taste, and in doing so stabilises feed intake. According to the current state of knowledge, it is also possible that the product breaks up the esters once more. The animals should be closely observed regardless. Whilst all these recommendations are useful, they do not fully solve the problem that the affected silage is not particularly suitable for feed. It is better to design the silage management process so that no esters are formed in the first place. This means that silage micro-organisms are monitored which are responsible for the development of the relevant initial substances. Based on previous investigations, it is known that this is predominantly ethyl lactate from a mixture of lactic acid and ethanol. Lactic acid is created by lactic acid bacteria and it is desirable, important for low-loss ensilage and must be encouraged.

Yeast goes into the silo along with feed

This means only ethanol remains. Ethanol is a metabolic product of unwanted yeast. This means that its development can be avoided by monitoring the growth of yeast. Yeast always enters the silo along with feed, and can breed to a greater or lesser extent depending on the storage conditions and silage management. Whilst they initially convert sugar into carbon dioxide and water in the presence of residual oxygen, when anaerobic conditions prevail then alcoholic fermentation is the by-product of such metabolism. Ethanol is the result. As yeast requires oxygen to breed, this simply means that all measures have to be taken to reduce the influence of air as a factor to a minimum. These include:

  • prompt storage and sufficient compression (also on edge and upper layers,
  • immediately cover and render airtight whilst using suitable materials,
  • no air should enter during storage.

These measures are assisted by using BioCool silage agent. BioCool acts as an active yeast inhibitor. Treated silage is not just more stable in aerobic conditions, it also exhibits far lower yeast growth and ethanol values at the time of removal. Strategic use of BioCool subsequently lowers the quality risk of "ethyl lactate production".

More information regarding silage management is available from Dr Sabine Rahn, tel. 0049 251 682-2289, sabine.rahn@agravis.de, and Dr Peter Rösmann, tel. 0049 251 682-2262, peter.roesmann@agravis.de, or go to www.silierung.de www.silierung.de .