With the exceptionally dry spring likely to have a knock-on effect on forage supplies, harvesting cereals originally drilled for grain as wholecrop in the coming weeks could help ease future shortages.

So says Francis Dunne of Field Options, who points not only to the guarantee of filling clamps with a valuable primary feed source but also to the opportunity the earlier harvest creates for establishing following crops.

“Data from our grass mixture trials at Harper Adams University (HAU) shows a 37% drop in production during April and May relative to forecast,” he reports, “and that’s likely to be similar on farms in many areas.

“Whilst recent rainfall is welcome and is providing a much-needed boost to grass growth rates, there will inevitably be an impact on future forage supplies. Farmers need to think now about strategies that will compensate for the forage dry matter that has been lost from first and second cut silage crops.

“Where farms have their own cereal crops originally destined for grain and straw, there’s an easy option to go down the wholecrop route. Alternatively, there may be arable farms in the area where the prospect of selling a standing cereal crop for wholecrop is good business, particularly where expectations for a grain and straw harvest are low following poor establishment conditions."

He added that in all cases, taking the cereal as wholecrop creates a far better window for sowing a following crop. Looking at past performance data from our HAU trials site, Mr Dunne said the best catch crop ryegrass has the potential to produce as much as 5 tonnes DM/ha as 25% dry matter silage by late September when sown following a July harvest.

It will then produce a similar tonnage in early May the following year and remain productive throughout 2021, if required. In the case of the arable farmer, harvesting cereals as wholecrop provides more options within the cropping rotation and could create the opportunity for something like fodder rape or turnips as a break that can offer an income as winter sheep keep. Crops such as this could produce more than 2000 lamb grazing days per hectare. At 50p/head/week this can generate £125/ha of supplementary income, said Mr Dunne

He added that wheat or barley are the preferred options for fermented wholecrop, which should be harvested when grain is at the cheesy stage and there is still some green in the foliage, with the aim being to achieve a 40% dry matter forage.

“It’s important to harvest at the optimum maturity and use a proven additive to ensure a rapid fermentation and minimise losses. It is only suitable for clamping, not bales,” he adds.

“Done well, wholecrop wheat or barley will be a really good complementary forage, fed at around 20-25% of the diet.”

Ken Stroud, livestock specialist at Volac also believes harvesting an area of cereal crop for fermented wholecrop silage could provide a lifeline for keeping cattle fed this winter in areas where spring drought has left grass silage clamps depleted.

He said that although there are still opportunities to boost flagging clamps with further grass silage cuts, grass has typically done the majority of its growing by the time we get through June.

Hence, assessing grass silage stocks in mid-summer fits perfectly with deciding whether to harvest some cereals for wholecrop.

“As well as maximising the yield and quality from remaining grass cuts, making wholecrop could be an excellent top-up for livestock farmers facing grass shortfalls this season,” says Mr Stroud.

“Wholecrop winter wheat can yield 12-15 tonnes of dry matter (DM) per hectare – which is more than three cuts of grass in a dry season. Spring barley is another option for wholecrop. Although it is likely to be lower-yielding, a lot of it has been planted this year. If you aren’t growing cereals, maybe look into buying a standing crop.”

As with any silage, achieving maximum feed value from wholecrop demands effective preservation, says Mr Stroud. Many farmers preserve it by fermentation, he says, because this is a low cost and straightforward method.

“Although fermented wholecrop can be made at crop dry matters ranging from 30-60%, cutting at 45-50% DM gives a good balance between providing moisture and sugars for fermentation and a good starch content in the cereal grain,” says Mr Stroud. “Starch content can be as high as 35%.

“Typically, this 45-50% DM level occurs as grain moves from the soft to hard ‘cheese’ stage but with no ‘milk’ detectable. Be careful not to overshoot this. Harvesting at higher dry matters will increase yield and starch content but reduce digestibility, and once cereal DM reaches 45% it can increase rapidly during hot weather by 2% a day.”

For the best preservation, Mr Stroud says as well as taking steps to aid the fermentation, it is vital to remember that, as a fairly dry and fibrous forage, wholecrop is highly prone to losses from heating. This is caused by yeast and mould growth, which is triggered by the presence of air.

Good consolidation to remove air from clamps is therefore imperative, he says. Rather than filling clamps in six inch layers before rolling, as typically recommended for grass silage, he advises just four inch layers to aid consolidation. The additive used also needs to inhibit yeast and mould growth as well as targeting improved fermentation, he stresses.

“Ecocool, for example, contains two strains of beneficial bacteria designed to tackle both of these issues. Treating isn’t expensive compared with a clamp of good silage,” he adds.

“Prior to sealing the clamp, another tip is to put a layer of at least a grab depth of fresh grass on top of the wholecrop and consolidate this too. This will add extra weight and an extra barrier against air to help keep the top of the clamp cool.

“Using the correct chop length is also important when harvesting wholecrop. Consider a chop length of around 2 cms to both aid consolidation and provide effective fibre in the diet for optimum rumen functioning,” Mr Stroud concludes.