Clamp management priorities play key role in lifting milk from forage

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.

Moving to a multi-cut system and reseeding 25-30% of all leys every year has done much to boost yields and quality going into the clamp, so the next logical step is to ensure as much of this as possible finds it way into the cows, says Tom Halton.

“You can put a shed load of work into producing as much grass as you can but if you don’t get that final bit at the clamp right, it’s all a waste of time and money.

“As an industry, I think we have a very different attitude towards protecting our hard-earned grass and silage compared to something like cereals.

“Grass is seen as a commodity that just grows and there’ll always be more of it, so we’ve grown up accepting 10 – 15% of waste at storage and feedout. But imagine if you lost 15 out every 100 tonnes of winter wheat that went into store. That would be totally unacceptable.

“When our clamps are full we’ve got something like 7000 tonnes of grass and maize potentially worth upwards of £200,000 and it is essentially sitting in the cold outside susceptible to rain, wind, pests and everything else.

“For the same value of wheat, it’s inside under a roof, locked away and carefully monitored to ensure it stays in tip top condition.

“So we’ve been rethinking how we look after our silage with the objective of keeping total losses down to below 5% and ensuring as many tonnes as possible of the grass we have already put a significant investment in, end up producing milk.”

The Haltons’ dairy business is used to pushing boundaries. Around 20% of all the milk produced goes to their own ‘Cow to Cup’ doorstep delivery service and the farm has won a range of awards over the years for welfare, herd health and productivity.

“At the moment we’re producing around 2500 litres/cow off forage and we’re keen to push this to 3500 litres/cow,” explains Tom, a second generation farmer at the company’s Chance Hall Farm, near Congleton, who runs the business with wife Karen and son Jack.

“We’re milking three times a day with an average yield of 11,000 litre/cow/year for the 500 milkers and really want to keep bought-in feeds down to a minimum. High volumes of top quality forage are absolutely key to the business’ future sustainability.”

Maize and grass silage are fed in a 50:50 ratio as the base of the herd’s TMR designed to deliver maintenance plus 25 litres/day, he points out.

“Our aim is to take up to six cuts of grass each year with first cut usually being taken in April. We usually get around 6t/acre on first cut and this will slowly fall to around 3t/acre for the last cut towards the end of June.

“Energy and quality stay high because of the frequent cutting and we’ve seen crude proteins reaching 20% in recent years.

“Very early maturing varieties mean we’re harvesting the maize from the start of October onwards, so we can be busy filling the clamps over an 8 month period. It’s a critical part of our business.”

Making sure the clamps are kept as free of air as possible during the filling process and that they can be resealed properly each time they are opened subsequently is of paramount importance with this approach, he says.

“We know that excluding air at all stages is important in getting a good fermentation so we pay a lot of attention to consolidating material as it enters the clamp.

“To make sure we get good compaction we have a buck rake and a tractor rolling material at the clamp at all times but even with this approach, along with using an appropriate additive, it’s been a bit more hit and miss than we would like in terms of producing the type of silage we want and avoiding too much waste.”

This brought Tom’s attention to how they were sealing the clamps and was the start of a transition away from a traditional multi-sheet approach to a single-sheet one.

Today, all clamps use high strength plastic side sheets and a single layer oxygen barrier film to seal the clamps.

Since moving from several layers of polyethylene sheets to a genuine oxygen barrier sheet, the difference in losses has been very noticeable, he says.

“Individual sheets are a total nightmare really, especially in windy conditions. It was such a difficult job that after a hard day’s silaging it was all too easy to leave the sheets off so you’re building waste into the system from the very start.

“Even when the clamp is fully sealed, getting an airtight join between the individual sheets is near impossible so that’s another area where your building waste into the system.

“Plus, as soon as the clamp was opened for feed out, you face the same problems as resealing, so accepting high levels of waste just becomes part of the process.”

Lucy Johnson of silage film specialists Silostop says a good system should easily keep waste and Dry Matter losses to 5% or even less.

“The starting point is sealing the sides of the clamp so no air can get in that way. It is possible get zero waste at the shoulders of the clamp using a modern film designed for this purpose.

“You then need to minimise the layers of material on the clamp so it is easier to manage and reseal. A single continuous ‘oxygen barrier’ film will keep air out of the clamp by avoiding any gaps and it is much more reliable and easier to use.

“Using a single cover sheet will then mean the clamp can be quickly and fully sealed whenever you want plus you’ll be cutting down on the amount of plastic being used on-farm.

“The majority of Dry Matter loss occurs in the top one metre because you can’t compact this and there isn’t the weight of the silage on the top layer.

“Imitation polyethylene oxygen barrier sheets are widely used and can help with surface waste but do nothing to reduce Dry Matter losses through shrinkage due to their porosity to oxygen.

“So that one-piece oxygen barrier is essential and making do with old single sheets with tears and gaps in between is just a false economy.

“Choose the right film and system and you should see a 6:1 return on your investment in terms of the extra silage you will get from the improved fermentation and reduction in wastage and DM losses.”

For Halton Farms the new system is based on a Silostop Max oxygen barrier for the main sheet and an ARK Secure cover. Tom’s son Jack Halton says the new approach has been a revelation.

“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.”

The approach is already taking the Haltons closer to their desired 4000 litre/cow off forage and should hopefully allow them to cut back significantly on bought-in feeds, he says.

“Grass and other home grown forages are still the most cost-effective feeds there are but they are not free. At a time when we’re seeing massive hikes in fertiliser, fuel and other inputs, you’ve simply got to preserve every kg of grass as efficiently as possible.

“Better sealing of silage clamps is such and easy win compared to many other approaches, so it really should be something every dairy and beef farmer takes a look at in the present circumstances.”