What reducing clamp loss from 15% to 5% could mean to your business

What reducing clamp loss from 15% to 5% could mean to your business
Reducing silage losses from 15% to 5% at the clamp can have a significant impact on the finances of a dairy operation, says Hampshire-based independent dairy nutritionist Martin Attwell.

“Grass energy is cheaper than concentrate feed energy regardless of the system so no matter how you farm, getting as much energy from your silage will always improve overall profitability.

“With high fertiliser prices and the dry spring in some parts of the country, it is even more important to prevent clamp wastage this year.”

“Using high oxygen barrier film and applying attention to detail when clamping not only saves money, it also improves milk from forage calculations.”

A typical silage clamp measuring 20m across and 50m deep filled to a height of 3m will contain around 600t dry matter (DM) of silage at 30% DM, he explains.

“So if you are able to cut clamp wastage from 15% to 5%, you are going to end up with an extra 60t DM of silage.

“Silage of 11.5 MJ ME/kg will yield 11,500 MJ ME for every tonne of dry matter. If we use a realistic value of 90% of that energy making it from clamp to cow, then that’s 10,350 MJ ME.

“The energy taken to make milk depends on its quality, but it’s generally 5.3 MJ ME per litre so the extra 10,350 MJ from silage would potentially produce 1950 litres of milk. So that extra 60t DM will produce an extra 117,000 litres of milk.

“At 40p/litre of milk that’s over £46,000 of extra milk revenue or, if you want to look at it another way, each 1.0t DM lost would need 0.75t of concentrate to replace it, so if you can save 60t DM of clamp loss you’ll be saving on 45t of extra concentrate.

“At £350/t that’s a saving of almost £16,000.”

Even with a moderate sized dairy herd, the financial impact of 10% extra forage is significant, he adds.

“If you’ve got a 250-cow herd producing 8,500 litres/year with a 6-month indoor feeding period you’re going to need to make around 700 tonnes DM of silage every year and if you are reducing clamp losses from 15% to 5% the effect on the bottom line is huge.”


Raising standards in silage clamp management and improving the quantity and quality of forage resulting is an increasingly important business objective for Somerset dairy producer Mark Humphry.

Run as a business partnership with wife Belinda and son Matt, Bartletts and Southey Farm, Isle Brewers, a Duchy of Cornwall tenancy, now has 360 crossbred commercial milkers.

“Producing lots of high quality grazing and silage is absolutely fundamental for us, so improving the efficiency of clamp sheeting has been a real priority in recent years.

“We changed to the Silostop Orange sheet and Anti-UV cover system recently and this has proved a great move. We were originally very sceptical that a thin sheet would do the job and hold up to everyday use.

“But we’ve definitely seen reduced spoilage on the top and this not only reduces the worry that this could find its way into the cows, it also eliminates the time spent removing waste from the clamp which can be considerable.

“It’s much simpler to use too. The Silsotop Orange all-in-one film that we use now means when you have finished with your silage clamp in the evening, it’s a really easy job in terms of covering the clamp back up so you’re more tempted to do it than waiting until the next day.’

Covering a silage clamp used to be about the worst job you could do on the farm, Mark admits.

“I used to reckon it took us longer to cover a silage clamp properly than it did for us to put the silage in there, but that has all changed now.

“It takes less time to cover the clamp properly at silage making, management is much simpler during the winter feeding period and we get better, more consistent forage to feed to the cows as well.”


With rising input prices across the board, Cheshire milk producers Halton Farms Ltd are targeting a 40% increase in milk production from forage with minimising silage clamp wastage one of their key priorities.

The farm’s new clamp sealing system is based on a Silostop Max high oxygen barrier film for the main sheet and an ARK Secure cover with the results being very impressive, says Jack Halton.

“In one move we’ve managed to simplify the silage making process, reduce stress at a busy time of year and increase the amount of high quality silage available for the cows.

“We’re definitely getting near that 5% figure now in terms of the much reduced waste we’re seeing and were easily heading towards 15% with the old approach.

“It’s not just the reduction in spoiled silage visible at the clamp, but there’s less material left in the troughs by the cows so the overall palatability and digestibility of our silage has obviously improved.

“Dry Matter intakes have definitely increased and the potential risk of mycotoxin problems resulting from poorly conserved grass is also much reduced.”