This year’s wet and gloomy summer has made it one of the most challenging ever to make good quality silage. And the difficulties look set to continue into the maize harvest – so what can farmers do to maximise their forage quality?
According to Pete Kelly, partner at Kelly Farm Consulting, maize yields are likely to reach an all-time low this year. Preserving as much nutritional value as possible will therefore be essential to help reduce feed costs over the winter. “The likelihood is that many crops will not reach full starch maturity since day length and temperatures are reducing, so many crops will be harvested with relatively high sugar levels in the immature cobs and green leaves,” he says.
“These green crops will be loaded with sugar so will be acid enough without an inoculant making the lactic acid even higher. Where there is a need to harvest by a deadline to establish following crops or to beat the weather there are likely to be even more problems.”
Wet silage – whether maize or grass – tends to over-ferment, leading to very acidic forage. However, Mr Kelly found that clients’ grass silage treated with a food preservative instead of a conventional inoculant did not drop below 4pH – even with dry matters as low as 21%. Food preservatives work by eradicating micro-organisms responsible for dry matter losses during fermentation and when silage is exposed to air, enabling clean fermentation to produce stable, palatable silage.
“Most maize crops are also likely to have a high fungal loading this year, which increases the risk of aerobic instability and waste,” he adds. “In my experience inoculant additives are unlikely to cope with these exceptional challenges this year.”
Of course, harvesting the crop is only part of the battle – clamp management is also critical, as a poorly ensiled crop can lose 25% of its feed value before reaching the trough. Eliminating oxygen from the clamp will protect against aerobic bacteria, yeasts and moulds, so rolling and sealing the clamp is critical.
John Mann milks 300 cows at Crooklands Farm, Blencogo, Cumbria, and tried to cut some maize in early October having run out of forage. “We got stuck and had to pull the machine out, as it was so wet.” However, he drills his maize early, and gets it growing away under plastic, so is confident that his yields and quality won’t be as bad as some other producers’ crops this year.
“Our second cut grass silage was very wet – but we’ve used Safesil food preservative instead of an inoculant for a couple of years, so it’s fermented well and is still quite stable,” he says. Although he doesn’t yet have sample results from second cut silage, the first cut averaged 36.6% dry matter, with 13.4% crude protein, 69.6 D Value and 11.1MJ of metabolisable energy.
“I find liquid products are more reliable and easier to use than the ones you have to mix yourself, and my silage has analysed better since changing how we do things – secondary wastage has also been lower as well.”
Last year Mr Mann also invested in a Silapactor, a four-tonne implement made with train wheels, to improve silage compaction when filling the clamp. Using a 125hp John Deere tractor with front-mounted buck rake, he rolls the clamp in fewer passes, saving fuel and improving silage quality. “I keep thinking we haven’t got enough silage, but it’s because it’s so well compacted that we’re using less space. It’s particularly good with lighter, fluffier crops like wholecrop and maize silage.”
He then sheets the clamp with two types of film, topped with black sheeting, and feeds it out as a total mixed ration comprising 16kg of grass silage, 11-12kg of maize silage, 5kg of Vitagold, 5kg of crimped wheat, 3-4kg of wholecrop and a protein blend.
“Good forage is so important to the cows’ health and productivity,” he says. “We’re averaging 9000 litres per cow, and although we lost two litres moving from first to second cut silage, I know some herds that lost eight litres. We’re seeing much less wastage in the trough, too – the cows are cleaning it up far better. We’ve always been quite careful with our silage, and it’s clear that attention to detail at every stage is the key.”