Learn how to tackle looming mycotoxin threat in maize silage

Experts from Lallemand Animal Nutrition UK & Ireland are warning farmers that the delayed maize growing season and expected late harvest will bring a higher risk of mycotoxin problems in silage. They will be sharing tips for preventing silage spoilage and feed-out losses at UK Dairy Day, on stand F23 in the concourse – plus giving away free pairs of cow socks!

Jayne Dandy, Lallemand Animal Nutrition UK & Ireland’s regional business manager for Cheshire, Staffordshire, Derbyshire and North Wales, will be at the upcoming UK Dairy Day event in Telford on 11 September.

She says the team is encouraging farmers to take action to control increased fungal loads from fresh forage.

Impact of delayed maize growing season

Mrs Dandy explains: “Despite recent hot weather, we’re expecting this year’s maize crop to contain a higher load of moulds and spoilage yeasts, because of wet growing conditions in spring increasing the risk of mycotoxin development.

“Much maize drilling across the UK was delayed and done in less favourable conditions, leading to an estimated later harvest. With the plant being in the soil for longer, this naturally increases the yeast and mould load.

“Wet weather also prevented many farmers from being able to travel on maize fields to apply fungicide, further increasing potential fungal loads,” she adds.

Why moulds create mycotoxins in maize silage

Mrs Dandy explains that the moulds present in maize crops become stressed when ensiled; this can lead to them producing mycotoxins that can have negative impacts on animal health, production and fertility.

“When maize is harvested and ensiled, the crop goes from an aerobic environment outside to an anaerobic environment within the clamp,” she says.

“Moulds thrive in an environment containing oxygen, so when fermentation starts in the silage clamp and their environment becomes anaerobic, the stress can lead to mycotoxin production – a mould’s self defence mechanism.”

How mycotoxins affect maize silage quality

Mrs Dandy adds: “The fermentation process does not break down mycotoxins effectively so any mycotoxins brought in from the field will remain in the clamp.

“Failure to control the other type of fungi present – yeasts – when ensiling your maize will lead to silage instability at feed-out.

“Then, when exposed to oxygen again, the dormant yeasts which survived fermentation will reactivate and start consuming lactic acid, causing the pH of the silage to rise.”

A normal silage pH has an inhibitory effect on the growth of moulds, she explains.

“So when the silage pH rises due to yeast activity, it creates the opportunity for mould growth at feed-out, and the risk of mycotoxin development rises once more.”

How to protect silage quality

Failure to address high fungal loads could lead to problems with maize silage quality, palatability, and overall herd health, so taking steps to manage microbiota is essential, Mrs Dandy says.

“Farmers should start by walking their maize crops now, checking for fungal infections on the cob or leaves.

“If there is an infection, there’s an even higher risk of costly mycotoxin problems and greater need for proactive steps to control yeast and mould.”

To help prevent moulds and spoilage yeasts from impacting silage quality, farmers are encouraged to use a crop- and condition-specific silage inoculant – which they can find out more about at Dairy Day.

Benefits of using a crop-specific silage inoculant

Mrs Dandy explains that trials at Lallemand’s Forage Centre of Excellence have shown that treating maize silage with a crop-specific inoculant, Magniva Platinum Maize, which contains the bacteria strains Lentilactobacillus hilgardii CNCM I-4785 and Lentilactobacillus buchneri NCIMB 40788, reduced yeasts and moulds by 99.9%¹.

“The inoculant also reduced heating caused by yeasts consuming lactic acid, which maintains a low pH in the silage, helping to ensure higher quality silage for feeding cattle.

“If producers are keen to get more from their silage to improve on-farm profitability and maintain herd health, come and find us on the F23 stand in the concourse at Dairy Day,” she adds.