With interest in more milk from forage, Volac is offering free consultations to help improve silage-making under its Cut to Clamp initiative.
Aimed at helping producers get more milk from silage, animal nutrition and forage preservation company Volac is offering a number of free consultations to help farmers produce consistently better silage.
Darran Ward, one of Volac’s nationwide experts conducting the consultations, says: “There is a huge amount to be gained from making better silage.
“Benefits can include spending less on bought-in feeds, improvements in cow health from a more forage based diet, and the satisfaction of making your business more self-sufficient by feeding more of what you grow.
“The consultations provide practical pointers to improve silage quantity or quality at various stages of the silaging process, including cutting, wilting, treating, harvesting, clamping and even feeding.”
In essence, Mr Ward says consultations involve three steps:
He says: “By combining all three elements, a comprehensive picture is built up to unearth areas for improvement.”
By conducting the consultation, Mr Ward says it is possible to pinpoint areas for improvement for making next season’s silage, but it can also provide tips to get more from silage already in the clamp.
He says: “The more milk produced from silage and forage, the better."
Although farmers are used to seeing silage analyses, the Cut to Clamp consultation goes further by simplifying results into a summary in two key areas, says Mr Ward.
Nutrient quality: For a picture of what the animal can take from the silage nutritionally, based on factors such as digestibility, energy content, sugar and crude protein.
Keeping quality: For a picture of the efficiency of the preservation, based on factors such as fermentation quality and ammonia production, and others.
Mr Ward says: “If the silage scored low for digestibility, we would ask about quality of grass to begin with.
“Is more regular reseeding needed? We would look at cutting date, because after heading, digestibility of grass falls by about 0.5%/day.
“Similarly, protein content of grass will decline as the season progresses, giving an indication of plant maturity when cut. Additionally, a breakdown product of protein, ammonia, gives a useful measure of keeping quality.”
Explaining this, Mr Ward says a high ammonia content is an indicator of a poor fermentation, because protein has not been fully preserved.
“We want a high sugar content, as low sugar can be an indicator of a poor fermentation by the wrong type of bacteria. These produce the wrong acids, as well as carbon dioxide, from sugar, which wastes energy.
“We want to produce lactic acid to ‘pickle’ grass into silage. This uses less sugar and is more efficient. So, as well as pH, we look at proportions of lactic acid to less desirable acids, such as acetic, propionic or butyric.
“Good silage would have five times as much lactic acid as other acids. A bad-scoring silage could have a ratio as low as 1:1.”
As well as silage analysis, a lot is gleaned by inspecting the clamp, Mr Ward says.
“We look at how uniform and tidy silage is in the clamp. An untidy silage face increases chance of air penetrating, resulting in wastage from aerobic spoilage, characterised by heating. We check the temperature at several points with a probe.
“How tidy is the floor? It shouldbe clean right up to the edge of silage to avoid contaminating the face with old silage.”
Visually, Mr Ward says colour will be checked, with olive green an indicator of good grass silage, while brown could mean a poor fermentation.“
We look at the amount of stem and leaf. You want mainly leaf, as stems are less digestible. Excess stem can mean cutting date was too late. You don’t want it to smell like vinegar or sickly sweet, but have a nice, clean smell.”
To assess consolidation, Mr Ward says straight horizontal lines showing in the layers of silage are a good sign. Wavy lines indicate uneven consolidation.
“The degree of difficulty pushing the temperature probe into the silage also indicates how well it has been consolidated, while the shoulders, which are harder to consolidate, will be visually checked.”
Mr Ward says: “We check whether side sheets have been used, and check how many layers are on the top.
“Many farmers think they do not need side sheets in a concrete clamp, but porous concrete is not as good as plastic for keeping air out.
“Ideally, we would look for an oxygen barrier film on top, with side sheets overlapping as far as possible over the top, then at least one black plastic sheet on top, and the whole thing properly weighted.
“It is important sheets are rolled back from the clamp face once opened to divert rain water from the top of the clamp from penetrating into the face.”
The final piece of the jigsaw is to discuss with the farmer how silage is currently produced.
Mr Ward says: “Starting with cutting, we review cutting date and height to see if there is anything out of order, and whether a mower-conditioner has been used to help speed up wilting.
“This is because the faster you wilt to the target 28-32% dry matter, the less sugar is used up by the plant continuing to respire.”
He says: “We review the full wilting process. For example, has a tedder been used? Most moisture is lost through pores in grass leaves, the stomata, which can lose up to 100 litres of water per tonne per hour. But they only stay open for two hours after cutting. Tedding within two hours of cutting gives better quality.”
Mr Ward says: “You need to use the right chop length for the stage of cutting and your target percentage DM, so you get the best consolidation in the clamp.
“We consider harvest machinery: was it a rapid forage harvester, or a slower trailed harvester or forage wagon? All these affect how long it takes to get the crop in the clamp.”
Mr Ward says he examines whether the right type of additive has been used: “Some people using a silage additive can suffer heat and mould in silage, but have applied a fermentation only additive with no effect on aerobic stability. Ensure you use the right product for the correct outcome.
“Often, an additive is used as a type of insurance. But think of it more as proactively managing the preservation process.”
“We check whether the clamp was filled in thin layers to aid consolidation, and was it rapidly sheeted?”
“We look at how silage is fed. For example, are you using a shear grab? Do you roll the top sheet back, rather than leave it hanging? The latter encourages spoilage from yeast and moulds.”
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