Maize is a valued component of dairy and beef rations and maximising its feed value and minimising wastage will contribute to reduced feed costs and improved performance.
Losses between the field and feed out can be as much as 45 per cent of the total available crop in dry matter (DM) terms.
Although some losses are inevitable when making maize silage because it is a biological process, the figure is closer to 13 per cent in the best performing units.
This is according to Roy Eastlake, national technical support manager of Lallemand Animal Nutrition, who says there are significant efficiency gains to be made on farms growing and feeding maize.
He says: “It is estimated that six million tonnes of maize is grown to feed cows in the UK, so if average DM losses are 15 per cent, this represents 288,000t wasted.
“The Maize Growers Association calculates maize costs £99/t DM to grow, meaning the UK livestock industry is losing £28.5m each year as a consequence.
“If the cost of replacing this wasted silage with concentrate is considered, the actual cost of this lost forage is nearer to three times this amount.
“Increasing intakes of high quality digestible forages will also help support good rumen function and promote better cow health and production, in turn improving margins.” There is no silver bullet to help reduce losses in the clamp, Mr Eastlake adds, as farmers need to combine high levels of management with the latest silage inoculant technologies.
This starts with planning ahead of harvest.
“Cleaning out the clamp thoroughly is very important, as it removes the remains of last year’s silage.
“Mud is a killer, so take steps to reduce the risk of contamination significantly reducing the mud being transferred from muddy tracks and yards into the silage clamp.
Willie Fleming grows 16 hectares (40 acres) of maize under plastic at Hillhead Farm, near Lockerbie, in the Scottish Borders. Mr Fleming drills an early maturing variety in May following a grass ley and the maize is generally harvested in early October.
He usually has to open the clamp soon after ensiling the maize, so always uses an inoculant to ensure aerobic stability throughout the season.
He says: “Last year we were able to leave the maize silage a little longer than usual before opening and we saw the benefit of this as it fed well and cows milked better as a consequence. We use the Magniva Platinum maize inoculant to keep the clamp cool after opening.
Our maize silage consistently analyses at around 30 per cent DM and 30 per cent starch and is a vital part of the ration.”
Joe Carter acknowledges he ‘grows good maize’ at Carpenters Farm in Wiltshire. He says: “We aim to harvest in late September and we walk the fields with our nutritionist from mid-August onwards.
“We look at cob development and any signs of disease to fine-tune harvest date to ensure we cut at the optimum time to achieve the highest feed value.”
Clamp space is limited at Carpenters Farm, meaning Mr Carter has to feed the maize almost immediately, so he has to make sure he takes every necessary step to minimise the risk of spoilage. “We clean out the clamp very carefully and we never re-use sheets.
We always have two machines on the clamp, one rolling and one levelling. We place a Silostop Orange cover over the silage and then the side sheets are placed up and over the top of the clamp. We then use weighted nets on top of this and sand bags.
Opening the clamp
“We always use Magniva Platinum inoculants, because we have to open the clamp after 15 days and we can see it makes a difference and is value for money. This year’s maize crop looks very promising so we hope to harvest by the end of September.”
“Cleaning out the clamp thoroughly is very important, as it removes the remains of last year’s silage”
“Check stocks of sheeting, silage film, netting and inoculant are sufficient and ensure there is adequate space available for maize to be stored.
“If more capacity is needed, consider investing in a silo bag to avoid waste.” During harvest, he highlights the importance of building the clamp in thin layers, which should be rolled well to eliminate all the air.
He advises sheeting with a proven oxygen barrier film, such as Silostop Orange, and placing a protective covering over this before weighting the clamp down to prevent air being sucked back in.
Mr Eastlake says using an inoculant costs very little compared with the high returns available if good management practices are observed throughout the silaging process.
He says: “Our range contains specially selected strains of heterofermentative bacteria which are ‘potent yeast and mould killers’.
“When the clamp is open to air, yeast and moulds present in the harvested maize will use the lactic acid and sugars present in the ensiled crop to ferment and cause heating and spoilage.
“Once the lactic acid is used up, other spoilage organisms will grow and generate more heat as they start to compost the silage.
“This results in a significant loss of energy in the silage and considerably reduced palatability and intakes leading to poorer animal performance.
“Where maize silage is managed poorly and no inoculant is applied, losses of DM can equate to 18 per cent of the DM due to aerobic spoilage and wasted silage.
“In contrast, with good management and the use of a correct inoculant, losses can be reduced to about 3 per cent.
“To achieve this, the inoculant must contain heterofermentative bacteria which drive the fermentation, producing lactic acid and acetic acid which is converted to very potent anti-yeast compounds.
“Magniva Platinum Maize inoculants contains a patented mixture of L.buchneri 40788 and L.hilgardii I-4785.
In trials, these organisms have been shown to reduce the numbers of spoilage organisms substantially.
“Using Magniva Platinum inoculants provides improved aerobic stability.
So after just 15 days of ensiling, should the clamps need to be opened early, the inoculant will help prevent spoilage and dramatically reduce waste.”
Tim Richmond, LG’s UK maize manager, says timeliness when harvesting maize is crucial.
To optimise forage quality and yield, growers must ensure DM levels are between 32 and 35 per cent at harvest.
Farmers should begin walking crops from early September to assess maturity.
Mr Richmond says: “To help determine the ideal harvest date, LG has developed the Maize Manager app, which will be launched in early September.
It consists of four sections, including the Harvest Manager tool, which allows rapid assessment of the crop in the field.
“The farmer should first select four or five plants at random from across the field.
Twist the stem of these plants near the base and observe the amount of moisture which comes out and match this to the on-screen guide.
Next, break open the cob and cut across the kernel to observe how much starch has been deposited within the grain and again match this to the on-screen guide.
“The app calculates the crop DM based on the moisture content in the green part of the plant and the cobs.
If above 32 per cent, it will advise starting harvest.
If below 32 per cent, the farmer can enter their postcode and the app will access the weather forecast and advise if the crop will be ready to harvest within the next week.” Mr Richmond says harvesting at the correct DM level is essential to ensure maize silage has the best feed value.
Harvesting too soon can mean starch formation is reduced leading to high sugar levels.
“Sugars are used up very quickly during ensiling, resulting in lost energy value at feed-out.
Conversely, harvesting too late increases lignin content resulting in a less digestible crop, which is more difficult to consolidate in the clamp, with lower energy levels and reduced DM intakes.”
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