The art of making the perfect silage

For the well-seasoned dairy farmer, it’s no secret that the making of perfect silage takes quite some practice. While in some respects, the principle is less problematic than hay-making - with the UK and Irish climate in mind, every now and then, Mother Nature throws us a little curveball to keep us on our toes.

So, after the long dry summer of 2020, we were blessed with rain… rain… and more rain over winter… (ok you can stop with the rain now!). And stop it did… ironically, for pretty much the whole of April 2021 - which is traditionally a rather soggy month associated with regular showers and epic conditions for grass growth. Instead, we might as well have been trying to grow grass in the arctic – it was that cold – which, we know grass isn’t a major fan of! Roll on to May and at last we receive some rain… and some warmth…and some more rain, and so the grass grows… but the rain doesn’t stop – well, not for very long!

So what does this mean for this year’s silage crop?

Reaping the rewards

Many, it would seem, are looking forward to relatively high yields - despite the challenging growing conditions. Others have fallen victim to reduced sward height and more open lays due to the rain arriving that little bit too late. But all is not lost, perhaps a second crop may be more successful? If only we could get the first one in! 

Make silage while the sun shines

While silage making isn’t as reliant on good weather as hay, with daily showers widespread, it’s impossible to achieve that crucial 28 – 32% dry matter target for optimum silage quality – even with the most rapid of wilts. 

So if you’re permanently refreshing your weather app to check the latest forecast, we can assure you, you’re not alone. We’re pretty sure there’s many a dairy farmer with a repetitive strain injury in their scrolling thumb right now, and pretty soon, there will be many waiting poised in their tractor cabs for the green light to cut grass.

The wilting hours

Wilting is a crucial time for seemingly supernatural goings-on relating to the sugar levels in your silage crop. A rapid wilt – with a cut in the morning and harvest later the same day – is likely to result in high sugar levels in the crop compared to a longer wilt. However, if wilting over 24 hours, a late evening cut is advised as there will be a higher sugar content in the grass at this time of day, but more will be lost the longer it is laid wilting.

Wilting wins…

1. Spread the cut grass straight out of the mower to help reduce wilting time.
2. Monitor dry matter in the field for that optimum 28 – 32%. The less time cut grass is left wilting, the less sugar will be lost.
3. Row up immediately before harvest and ensure your machine is set up on a flat surface and not scraping up any soil to contaminate your silage crop.

Chop length V’s clamp health

The old adage that long chop material is essential is something of an old wives tale. In fact, it’s a little more scientific than that, with an impact on overall clamp health.

As a general rule, for a crop with less than 22% dry matter (it’s certainly going this way this year!), a 10cm chop length is recommended to reduce the occurrence of clamp slippage at feed-out. For a crop of 22-25% dry matter, chop length can be reduced to 7.5cm, from 25-30% dry matter, the chop can be further reduced to 2.5 – 5cm, but above 30% dry matter, the chop length should be no greater than 2.5cm.

The exception to this rule is a really good quality silage with high digestibility. In this case, a 5cm chop length is suggested to counter the reduced fibre in the crop and reduce slippage in the clamp.

Consolidate your clamping efforts

Treat your clamp as if it were an airbed you’re trying to pack away after that weekend camping trip. Playing close attention to the loading of your clamp is crucial – unlike packing away your airbed, not purely for the purpose of trying to fit your whole crop in there, but squeezing as much air out of it as you can is vital.

Trapped air = reduced fermentation quality and improved conditions for aerobic instability at feeding.

Clamping top tips

1. Create even layers of no more than 15cm thick.
2. Compact each layer evenly before adding the next.
3. Prioritise your clamping procedure over your harvesting – it’s essential to get this right.
4. Seal your clamp like you’re packaging a parcel to send overseas. Minimising oxygen in the clamp is paramount for optimum silage quality.
5. Sheet all sides of your clamp, securing the bases with gravel bags to help reduce Oxygen ingress, which will reduce the quality of your fermentation.
6. Seal your clamp for a minimum of two months. During this two-month period, the yeast population that is the initiator of aerobic spoilage at feeding is reduced. 

Care for your crop doesn’t stop there…

Unlike hay, which generally, once stacked in a dry barn, is pretty safe from spoilage, the care of your silage clamp continues through feed-out. 

Keeping the clamp in front of the silage clean enough to eat your dinner from, majorly reduces the risk of compromising the rest of your crop. Dirt and spoiled silage simply provide a breeding ground for unwanted nasties that we really don’t want in our clamps.

Maintaining a straight face is something dairy farmers are well versed at, but when it comes to your silage clamp, it’s top of the list in best practice. A shear grab or defacer is invaluable when feeding out, in order to maintain the minimum exposed surface area and reduced opportunity for oxygen ingress and resulting nutritional losses.

Key take-aways

Aerobic spoilage is the number one issue affecting silage quality globally, a big cause of which is poor clamp compaction.

Get the process right and you increase both productivity and profitability in your dairy herd.

Tell us your silage stories

With the weather forcing a late start in the season, we appreciate there aren’t many tales to tell from 2021 as yet, but we’d love to hear how your silage harvest pans out. Follow Megalac on social media to share your #silagestories.