Making good quality silage depends on many factors, not all of which can be influenced. But planning ahead means it should be possible to take control and avoid many potential pitfalls.
Mowing when the grass is at the correct maturity is the single most important factor determining the quality of the silage made.
Getting the timing right should not be guesswork, instead, carrying out a weekly pre-cut grass analysis in the period leading up to first cut is the best way of judging whether the grass is ready.
This is according to James Duggleby, marketing and product manager for Krone UK, who says timing is of the essence when it comes to making the best silage.
“The days of making silage on a set date should be behind us now, as the weather conditions during each year are entirely different.
One of the biggest causes of reduced energy value of silage is cutting grass too late.” To ensure all stages of the process are carried out in a timely manner, check machinery is in good working order so there are no unnecessary delays or false starts, Mr Duggleby says.
He urges farmers to carry out all the necessary maintenance checks on equipment well ahead of time, especially mowers, tedders and rakes.
“If buying new equipment, always consider carefully the size you need, to ensure it is compatible with the other machinery you have already.
Assess the farm needs, labour availability and handling capacity to maximise efficiencies and silage quality,” Mr Duggleby adds.
“Mowing in the early afternoon is desirable because the dew should have dried and the sugar levels in the grass are highest at this time after the plant has photosynthesised.
Aim to cut grass at 80% moisture and wilt it down to 25% dry matter for a clamp, or 35-45% if it is to be baled.
“When deciding whether or not to use a conditioner on the mower, consider the advantage of faster wilting because the conditioner breaks the waxy cuticle on the leaf, speeding up water loss.
Balance this against the risk that if it rains, the leaves will reabsorb water more quickly”, Mr Duggleby says.
Managing the wilting process correctly is also influential, he adds.
“Wilting should be as rapid as possible and ideally should be within 24 hours.
Tedding helps to speed up wilting time and mixes the grass to give a more uniform wilt and improved consistency, with fewer hot or wet spots in the clamp.
Be careful to avoid ‘recreational tedding’ as it can cause the grass to become too dry or damaged.
“Row up just before harvest so the grass quality remains uniform.
Leaving grass too long in the swath will result in the top wilting more than the bottom.
Create an even, boxshaped swath for a smooth, consistent flow into the harvester,” Mr Duggleby adds.
‘If you do not measure it, you cannot manage it’, is the old adage which is frequently used in relation to many aspects of crop and livestock production.
It is certainly relevant to making silage and with a range of new technologies available, the process of measuring silage yields and quality is now easier and almost instant.
Forage harvesters can now be fitted with Near Infrared Spectroscopy (NIRS) systems.
NIRS sensors work by shining a beam of broad-spectrum near-infrared light at the chopped grass as it is blown out the discharge spout.
Forage wagons can be easily fitted with weigh cells to give load by load analysis.
Forage harvesters can measure the volume of the crop passing through the feed rollers for constant analysis.
Combining this with trailers equipped with weigh cells allows for improved accuracy.
Both options make it possible to carry out yield mapping of fields.
If coupled with detailed soil analysis, this can allow for variable rate fertiliser application and can also record overall fresh weight yields.
Investing in the right harvesting equipment for the farm is critical to optimise the quality of silage and the cost effectiveness of the operation.
It is not just about picking the right machine, but it is also about scale and combinations.
Choosing between a self-propelled forage harvester and a self-loading forage wagon is the first decision to make, according to Mr Duggleby.
He says cost will inevitably be one of the main factors to consider.
“Prices for the smaller forage harvesters on the market generally start at around £250,000, whereas a medium sized forage wagon can be purchased for around £80,000.
There is also the cost of the tractors and the trailers required for the forage harvester.
“Depending on the scale of the operation, the costs per tonne of silage harvested will eventually even out for these two options, but for those with smaller acreages, a forage wagon is usually a more affordable option.
It is also important to consider labour availability, as more people are required for the forage harvester.
“The length of chop differs between the two machines, with the forage harvester producing a uniform chop of between 3mm to 25mm, depending on drum configuration, and generally better suited to making silage for a total mixed ration with additional roughage.
The forage wagon will usually deliver a more varied chop length, averaging around 40mm, reducing the need to add additional straw or another source of fibre,” Mr Duggleby adds.
Ultimately, the choice between the two machines will come down to the individual circumstances on a farm and the available capital for investment and many farmers may choose to use contractors instead.
“Whether a farmer chooses to own and operate their own harvesting equipment, or to employ a contractor, it is important to consider which system provides the greatest flexibility, fits with available manpower and is able to take advantage of good weather windows,” Mr Duggleby says.
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