Wet threat to silage controlled by preservative

Good farming practice and the right choice of additive have turned potentially difficult silage cuts into good quality forage for a high yielding herd.

Like many farmers and growers, the Riding family have chopped and changed silage additives over many years. So, last year, when they were faced with a late, wet cut of grass silage, they were undecided about which product to use. They were concerned about adequately wilting the crop in potentially wet, cool conditions, and they were concerned it could be contaminated with soil. This posed the risk of clostridia entering the forage and continuing to thrive and spoil the silage in the clamp.

Farming together at Goosnargh Lodge near Preston, the three generations – grandfather, Fred, his son, Mark and grandson, Jake – were all well aware of the damage this could cause. With a herd of 180 Holsteins giving 10,522 litres at 4.47% fat and 3.44% protein, they were not prepared to risk the butyric fermentation which could arise in these conditions. This could potentially restrict intakes and hit performance and metabolic health.

So, when the family read about MultiMax, the preservative launched by Kelvin Cave last year specifically for low dry matter (DM) silage, they were keen to find out more (KnowHow, Spring 2025).

Michael Carpenter, Kelvin Cave’s technical director explains: “We brought MultiMax to the market last year specifically to help producers make silage in multi-cut systems.

“Tight weather windows are often a feature of these systems where both soil contamination and slurry residues can be a concern,” he says. “There may also be less time for wilting, so low dry matter is a risk when silage is being cut against the clock.”

These same dangers prevail in autumn cut grass, which is why the Riding family decided to give MultiMax a try when making their final cut of the year. At that time, low sugars are also a seasonal hazard, risking insufficient substrate for a bacterial inoculant (the alternative to a preservative) to achieve a desirable fermentation.

So, the Ridings tried MultiMax for the first time last autumn, cutting and clamping their ryegrass sward in late September.

“There would be a risk that clostridia would prevail in these conditions, converting sugars into undesirable butyric acid which would create unfavourable and unpalatable compounds in the silage and lead to dry matter and energy loss and compromise animal health.

“Instead, we would always recommend a preservative, and MultiMax is one which would particularly suit this situation.

“It contains sodium nitrite, the most potent inhibitor of undesirable clostridia we can include, which is why this ingredient is commonly used in human food preservation,” he adds.

“In silage, it rapidly and selectively kills undesirable clostridia and their spores, and together with other ingredients, reduces pH and ensures the forage is well conserved,” he says.

“In fact, this is the only silage additive we know of which has actually been tested with heavy levels of soil and clostridial contamination, which is why I have such confidence in recommending it when these things may be a risk.”

Using it for the first time last autumn, the Ridings say they’ve been pleased with the outcome and have ordered enough for more cuts this year.

Mark says: “Last year, fourth cut was certainly wetter than I’d have liked and we had to make it in three attempts as the weather was so catchy.”

Not expecting a vintage crop, he says he is pleased, not only with the silage analysis, but also in how well it has preserved and fed to his cows.

“Unfortunately, we did have some slippage, which is a risk when the crop is wet, but the silage stayed completely cold when it slipped into a pile from the clamp, even though it was exposed to air and not used up for several days,” he says.

The silage analysis also bears out the favourable fermentation, with ammonium nitrogen (as a proportion of total nitrogen) exceptionally low at 2.7%.

“This reflects an excellent fermentation, very little breakdown of protein and suggests a rapid drop in pH which prevents unwanted bacterial activity,” says Michael.

This was demonstrated in a pH of 4.1 which is considered optimal for this type of silage.

“We now have several products on the farm to give us the flexibility we need in Lancashire’s unpredictable weather,” says Mark. “We will try the Activator range of inoculants as conditions dictate, particularly using Activator+CA on higher DM cuts where aerobic spoilage is a risk on clamp shoulders and tops, but will use MultiMax in cuts where fermentation would be challenged by low dry matter.

“We completely understand the importance of having the right product for the conditions, having experienced DM losses when the wrong choices have been made in the past,” he says.