Livestock farmers who experience common grass silage problems of heating, clamp slippage and mycotoxins, should reassess silage-making techniques.
That is the message from Freya Webber, Volac technical business manager for Scotland and Northern England, who says these are the three biggest grass silage concerns she hears from farmers. She offers tips to help farmers respond.
Silage heating
Although often considered a maize and wholecrop cereal silage problem, heating is also common in grass silages, says Freya. Usually it is due to a combination of grass being ensiled too mature and too dry, she explains, which contributes to inadequate consolidation, allowing yeasts and moulds to grow in the clamp in the presence of air. It is also not helped if a silage additive is used that does not tackle yeasts and moulds, she adds.
“If silage is heating, it’s losing a lot of energy,” says Freya. “It’s not that grass silage is intentionally harvested late or made drier. It’s just that for various reasons harvest gets delayed or grass ends up being wilted for too long. To prevent this, harvest before grass becomes excessively stemmy, and check its percentage dry matter (%DM) regularly during wilting, aiming for an optimum 28-32% DM.
“If grass does end up being over-wilted, be prepared to chop it shorter to help overcome the difficulty of compacting drier silage, and make sure the correct type of additive is used.
“If you’ve had historical problems with grass silage heating, consider a dual-action additive, such as Ecocool, that not only aids fermentation but also controls the yeasts and moulds that cause heating. Ecocool has been shown to keep grass silage cool once opened to air for more than 15 days.”
Clamp slippage
The increasing problem of silage slippage can occur for multiple reasons, says Freya – including silage being made too wet or from grass that is very leafy and lush; incorrect chop length; uneven clamp consolidation; and wide and/or over-filled clamps.
“Several of these can contribute to silage towards the bottom of the clamp collapsing due to the weight of the silage above, resulting in the clamp face slipping,” Freya explains.
“It’s unlikely there’s a single solution. However, steps to consider include adjusting wilting technique to increase the %DM if silage is being made too wet or lush – for example by introducing tedding – and adjusting the chop length. Generally, wetter or younger and leafier silage needs a longer chop length to help bind it together in the clamp.
“With wide clamps, divide them into narrower ones if possible. Also, make sure the entire clamp is consolidated evenly from top to bottom and avoid loading clamps too high. Lusher, younger grass will have more tender cells, which are more easily ruptured under pressure. So if the crop is lush and below 30%DM, it’s especially important not to over-fill them – for example, don’t fill them much more than 3m high.
“Care should always be taken around silage clamps, but especially if the silage is moving as the timing of a slip can’t be predicted.”
Mycotoxins
Mycotoxins, produced by moulds, can cause a wide range of livestock health problems, says Freya.
“Taking steps to minimise mould growth – such as fully removing air from the clamp with effective consolidation and avoiding slippage – will help to reduce the risk,” she explains.
“With maize, ensiling with Ecocool has also been shown to prevent both mould growth and significant accumulation of certain mycotoxins when the silage was exposed to air.
“If mycotoxins are suspected, consult your vet and get the silage checked using the Mycocheck service, which tests for a range of different mycotoxins. If mycotoxins are identified, a specialist mycotoxin remediation treatment, such as Ultrasorb, will be needed to reduce the mycotoxin burden in the silage in the final feed fed to the livestock,” Freya concludes.
By making timely adjustments to harvesting, clamp management, and additive use, farmers can significantly reduce these common silage problems and ensure safer, higher-quality feed for their livestock.
Further information from:
Freya Webber Technical | Business Manager – Scotland and Northern England Volac International Limited Mobile: 07525 809447 E-mail: Freya.Webber@Volac.com
Jackie Bradley | Product Manager Volac International Limited Tel: 01223 206 827 Mobile: 07736 967665 E-mail: jackie.bradley@volac.com