Cut to Clamp Maize, being launched by forage preservation and animal nutrition company Volac, follows a similar initiative that the company introduced last year for grass silage.

It aims to help farmers minimise maize feed value losses through each of five stages of: planning, harvesting, treating, clamping and feeding, explained Volac business manager, Darran Ward, speaking at the launch of the initiative. Advice will be available via a dedicated website, literature, and free on-farm silage audits, he said.

“We know from two years of surveys among dairy farmers that there is strong interest in maximising the amount of milk produced from forage,” said Mr Ward, “with a massive 99% of respondents saying this was either extremely or very important.

“However, there was also confusion about the scale of losses that can occur in maize due to its two main enemies of poor fermentation in the clamp and spoilage, which causes heating. Cut to Clamp Maize aims to address these.

“With grass clamps already opened to supplement grazing because of the drought, producing good maize silage could be a lifeline for many livestock farms.

“Typically, losses from aerobic spoilage or heating, which is caused by yeasts and moulds in the presence of air, will deplete a 1,000-tonne maize clamp by 200 tonnes. Maize silage costs about the same to produce per tonne of dry matter as three cuts of grass silage, but you only have one harvest to get it right.”

Volac silage microbiologist, Philip Jones, agreed and said aerobic spoilage also reduces feed quality and causes mycotoxins. Although maize does ferment more easily than grass silage, he said losses from inefficient fermentation can be higher than farmers may think – at as much as 8%.

“Nowadays, more maize is also being harvested before it starts to die back,” said Mr Jones, “and there is an argument that greener leaves with a higher moisture content will need more help with fermentation. During an efficient fermentation, beneficial bacteria produce beneficial acids, which then pickle the maize to preserve it.

“There’s no single step to maximising fermentation efficiency and minimising heating. It needs a joined-up approach. If we can improve farmers’ understanding of what happens in the maize clamp, it becomes much easier to take the right steps to minimise losses.”

Farmers wanting further information on Maize Cut to Clamp can visit:

Philip Jones and Darran Ward highlighted some of the key points for the five stages of Cut to Clamp Maize as follows:

1. Planning – for an efficient harvest and so the clamp is in good shape

  • Keep your contractor informed of the anticipated harvest date
  • Minimise contamination from last year’s mouldy silage and from soil carried on machinery by cleaning the clamp and surrounding area thoroughly
  • Start to make the clamp airtight by lining walls with polythene, leaving sufficient overlap with top sheets

2. Harvesting – to optimise starch content and set the crop up for consolidation

  • Aim to harvest at 30-33% dry matter. Too dry is more difficult to consolidate. Harvesting too early means starch in the maize kernels is not fully formed
  • Harvest modern ‘stay green’ varieties while still green – before they have died off
  • Resist the temptation to cut the maize plant too low at harvest in search of extra bulk – the base of the stalk has little nutritional value and increases the risks of soil contamination and mycotoxins
  • Consider a chop length of 1.5 to 2cm to make consolidation easier

3. Treating – for greater control of the processes in the clamp

  • Minimise losses by choosing the right additive – e.g. one containing beneficial bacteria targeted at both:
    • Improving fermentation
    • Reducing heating losses from aerobic spoilage

4. Clamping – to aid fermentation and starve spoilage organisms of oxygen

  • Fill in even layers no more than 15cm deep – the maximum that can be consolidated effectively
  • Apply salt into the top few inches of the clamp – which are particularly vulnerable to aerobic spoilage
  • Calculate the weight of machinery needed to consolidate to around 750 kg or more of fresh weight of maize per cubic metre.
  • Consider an oxygen barrier film on top
  • Use a single 1000-gauge or two 500-gauge polythene sheets on top of that, pull tight and fold together with the side sheets to seal
  • Protect from damage with a woven sheet over the top. Weight with mats, gravel bags, touching tyres or bales. Net to stop birds, and bait to stop rodents

5. Feeding – to protect your investment

  • Minimise air exposure using a block cutter or shear grab to keep the face tidy and by moving the face back quickly (aid progression across the face by using narrow clamps or dividing the clamp width)
  • Cut or roll the top sheet back as you progress through the clamp, keeping weights on the front edge. Never leave it hanging over the face as this encourages mould
  • Clean up silage that falls off the face to minimise mould spores contaminating clamp