Additional effects of lactic acid bacteria

Mode of action of biological silage additives are wide-ranging

In the case of biological silage additives, their primary effect in silage is usually the main focus. Today, additional effects beyond the primary effect contribute significantly to the efficiency of the products. This also applies to Siloferm and BioCool. It is well known that Siloferm supports the desired lactic acid fermentation and significantly reduces silage losses. This not only results in a higher volume but also in more nutrient-rich feed, which ensures a higher feed performance.

For example, using Siloferm produces at least 400 litres more milk per hectare of grass. When BioCool is used, the main effect is during feeding out process. Heating up and moulding are therefore avoided. This also means a significant increase in basic feed performance, with an increase of up to 1,000 litres more milk per hectare of maize silage.

This mode of action of biological products is well known. But is this still sufficient under current silage conditions? Additional effects are becoming increasingly important. This also applies to Siloferm and BioCool. The lactic acid bacteria contained in both of this products perform better and therefore differ significantly from other lactic acid bacteria.

Additional effects beyond the initial effect are now an important criterion for classifying product quality. Important additional effects of Siloferm and BioCool are, for example, control of the pH value in the silage and cell wall decomposition. Many silages today are significantly richer in lactic acid than in the past. Why is not yet fully understood, however, there are repeated reports of reduced feed acceptance of these acidic silages. To what extent the lower pH-value also influences the acidosis risk also cannot be answered yet. Many farms already use buffering substances, e.g. sodium bicarbonate, as a prophylactic treatment in feeding, which causes additional costs. However, the low pH values in combination with the high lactic acid content can also become problematic if yeasts were active at the same time and could produce alcohol.

Lactic acid reacts with alcohol to form esters, detectable by a strongly pungent, adhesive-like odor. Here too, the animals react by not feeding. If BioCool is used, the lactic acid bacteria contained in it control how low the pH value is decreased via their secondary metabolism. If the critical growth limit is reached, the Lactobacillus buchneri contained in the product switches its metabolism. Lactic acid is metabolised into a nutrient and is converted into acetic acid and propylene glycol. Over-acidification of the silage and the resulting problems during feeding are reliably avoided. Since the effect of BioCool is also directed against yeasts, treated silage contains less alcohol and lactic acid fermentation and pH-value are controlled, no esters are formed. A further additional effect results from the formed propylene glycol, which can be used by the animal in the case of a negative energy balance and thus reduces the risk of ketosis.

In order to reach the sugar in the plant cells easier and faster, the lactic acid bacteria contained in Siloferm and BioCool also produce certain extracellular substances (ECPS). With their help they create many small entry points. These break points in the cell wall are later also used by the rumen flora. Cell wall components or raw fibres are thus easier to digest and can be degraded faster. This also promotes the feed efficiency of treated silages.

Further information is available from Dr. Sabine Rahn, Product Manager silage fermentation telephone +49 251 . 682-2289, sabine.rahn@agravis.de