Step 1 . Cutting

What is the best stage to cut your silage? Plus, why later and lower silage cutting could mean you lose more than you gain.

As grass approaches heading, yield increases. However, leave it too late and protein, digestibility and metabolisable energy all decline. After heading, the digestibility of grass falls by about 0.5% a day.

It's true, delaying cutting might produce a heavier crop. But because it's nutritional value will be lower, it won’t have the same ability to support milk production. Plus, losses are actually higher than with a lighter crop. So the yield benefit isn’t as great as you might think.

Independent Silage Expert, David Davies explains the key things to think about when cutting grass for silage making.

TOP TIP: Consider type/stage of crop, weather conditions,
contractor availability and farm pressures.

For good quality silage at an acceptable yield, cut just before heading.

Similarly, although it might be tempting to cut low as this increases yield, the stem base is the part of the plant with the lowest digestibility. So again, overall quality will be improved by cutting higher.

On top of that, dead material in the sward base contains higher levels of undesirable micro-organisms that hinder fermentation and increase aerobic spoilage.

And cutting too low increases the risk of introducing soil micro-organisms, such as clostridia, into silage, increasing the risk of a poor fermentation and reducing it's feed value, or even potentially contaminating with listeria.

Multi-cut hints and tips

Before you switch to multi-cut, start by making sure your contractor (or any other labour required) will be available. Typically, first-cut silage may have been taken around mid-May, depending on location. But multi-cut could take that well into April, especially further south.

When it comes to cutting, avoid cutting too low. Remember, you want rapid regrowth, because you'll be cutting again in a few weeks' time.

Remember also, when reducing cutting intervals to maybe 4-5 weeks, regrowth will require less nitrogen fertiliser than if cutting every 6 weeks or so.

Plus, it's also vital to stop slurry contamination.

Leave a long enough interval between applying slurry and each cutting date (including before first cut). And never surface spread the slurry. Instead, inject it. Failing that, use a trailing shoe.

Another advantage of cutting grass at a younger growth stage is that it can reduce silage variability across the clamp face.

With standard cutting, half the field might be in head when cutting and the rest not. Even the process of chopping and moving it won't mix it enough, and it can take days to get across big clamps at feed-out. Each day effectively therefore becomes a different ration. And variability costs milk yield.

Volac and Germinal have developed a 10-point multi-cut grass silage checklist, designed to help you get the most from your grass silage making process. 

Consider type/stage of crop, weather conditions,
contractor availability and farm pressures.
— Dr David Davies, Independent Silage Consultant

Want to learn more? Take a look at the next step.