Be aware of potential silage pitfalls of this season’s forward grass growth

Long, decaying grass on silage ground
Long, decaying grass on silage ground

Dairy and other livestock farmers facing this season’s widespread forward grass growth need to be aware of the pitfalls this could pose to silage making, if they are to maximise silage yield and quality, says Ecosyl product manager Derek Nelson.

According to Mr Nelson, old grass that has continued growing through the winter will not only be of poorer quality than fresher grass, in terms of energy and protein, but will also have a higher loading of naturally-present undesirable microorganisms that could add to clamp losses.

“Wherever you have old grass that has been growing since autumn, it is of poorer quality,” he says.

“Instead of having young, leafy growth, some of it will be dying back, which provides nutrients for a wide range of bacteria and fungi to grow on. This will increase the numbers on the crop at harvest, increasing the risk of a poor fermentation and reducing aerobic stability at feedout, both of which will lead to significantly higher losses.

“If slurry is also applied too close to grass cutting, this adds to the problem by introducing more undesirable bacteria, such as enterobacteria and clostridia.

“Also, compared to shorter and more open grass crops, thicker grass crops create an ideal microclimate for undesirable microorganisms to thrive. Extended wilting will encourage their growth further.

“In these circumstances, it is even more important that wilting is rapid and the clamp filled and sealed quickly. This will be particularly effective at limiting yeast and mould activity.

“But you also need to ensure the fermentation gets going quickly as a rapid pH fall will inhibit the undesirable bacteria”, adds Mr Nelson. “This is brought about by lactic acid bacteria, which are normally in short supply on fresh crops. An effective silage inoculant will apply large numbers of specially selected strains of lactic acid bacteria, ensuring a fast, efficient fermentation that will inhibit the undesirable bacteria quickly.

“This will reduce DM losses but has other benefits too as it preserves more true protein and increases digestibility, both of which are beneficial for animal performance.

“A good quality silage inoculant offers benefits even in good silage-making conditions, but the benefits can be even more obvious in seasons like this when grass growth is more challenging.

“Bear in mind that all inoculants are not the same, so always check there is independent evidence to back any claims, especially those for improved animal performance,” he adds.