Farmers are being encouraged to test first-cut silage before feed-out amid reports of high levels of ash in some silage crops.
While average ash levels are looking similar to last year, in some areas they are higher than normal, which could pose a cause for concern.
This is according to Liz Homer, ruminant technical development manager at Trouw Nutrition, who explained that silage samples were extremely varied this year.
She said: "It's important to compare your own silage analysis to previous years, and analyse forages in the clamp regularly to check for any changes.
"This could mean that you need to rebalance your ration and rethink mineral supplementation in more detail."
Anwen Jones, regional business manager at Lallemand Animal Nutrition, added that there was a greater number of first cut silage samples with ash levels higher than 7%, and even above 10%, in comparison to silage sample results from the same period last year.
She said: "If you cut during the wet spell in May, take a close look at your ash results before feeding first cut, as there could be an increased risk of soil contamination in your silage."
Ms Jones said this was a cause for concern as any level above 6-7% is an indication of soil contamination in grass silage.
If farmers' first cut silage is above these levels, Mrs Jones said there were simple practices that could be taken to mitigate the impact on cow health.
"Ensure all ensiling equipment is as clean as possible before cutting at the correct height can help prevent contamination," she said.
"However, many of this year's first cuts were harvested during less than ideal ground conditions - with soil contamination an inevitable result."
To manage the risk of contaminated silage, Mrs Jones recommended testing silage to assess its ash content, and supplementing animals with products that contain live and dead yeast components, such as Levucell SC Toxisorb.
She said: "Using a rumen-specific live yeast in combination with inactive yeast components such as yeast cell walls will not only favour a positive microbial balance in the rumen and aid digestive resilience to contaminated feed, but it will also improve fibre and total diet digestion improving feed efficiency and milk performance."
How do I manage contaminated silage?
Her other tips for managing contaminated silage are:
• Do not be tempted to feed highly contaminated, or visibly deteriorating silage to any animals as this can cause both short- and long-term issues ranging from reduced feed intake to diarrhoea and in extreme circumstances even death
• Dilute suspected low level contaminated silage with other cuts of forages to minimise overall dietary ash content
• Ensure high levels of hygiene throughout the feeding regime to reduce the risk of further microbial contamination by regularly cleaning troughs, keeping feed wagons clean and keeping vermin and birds away from feed
