Effects of mycotoxins

When animals consume contaminated feed, the consequences can be wide ranging and costly. Reduced feed intake and weight loss are common, as are drops in milk yield, poorer fertility and compromised reproductive performance. Herds and flocks may also show increased lameness, erratic behaviour or neurological signs. These effects can be subtle, so producers may not immediately link them to mycotoxins, yet the cumulative financial impact can be significant. All classes of livestock are vulnerable. Ruminants such as cattle and sheep and monogastrics including horses, pigs and poultry can all be affected. Mycotoxins are produced by fungi and once formed, are chemically stable; some resist heat up to 400°C. They enter the food chain through grazing pasture and conserved forages such as hay, baleage and silage, with maize silage particularly at risk. Grain-based feeds including cereals, palm kernel and copra are also common sources. Environmental stresses that damage plants, warm humid conditions or persistently cold damp areas increase the likelihood of fungal growth and toxin formation.

NIWA’s climate forecasts indicating warmer, wetter seasons across our motu suggest conditions favourable to fungal growth will increase and persist for longer, making higher mycotoxin levels in feed more likely. Detecting mycotoxins is challenging. Production can be sporadic, visible mould may no longer be present while residues remain, and there are more than 300 known mycotoxins, each capable of different health effects. Laboratory testing is useful but costly, and results depend on sampling, storage and local conditions. When multiple mycotoxins occur together their effects can be cumulative, producing more severe and prolonged impacts than a single toxin alone.

Given these risks, prevention is better than cure. On a production checklist mycotoxins may sit lower than more obvious constraints, but they should not be ignored once other limitations have been addressed. Fortunately, there are practical steps farmers can take to reduce exposure and protect performance:

• Avoid grazing high-risk areas during periods of elevated mycotoxin pressure, especially where facial eczema or ryegrass staggers have occurred.
• Use silage inoculants and maintain good silage face management to limit fungal growth.
• Incorporate a mycotoxin binder either continuously or during known high risk periods. Binders vary in complexity and cost, and sometimes finding an effective binder is more urgent than identifying the exact toxin.
• Limit animals’ access to contaminated feed by offering alternative forages such as hay or baleage and ensure supplementary feeds contain a proven binder, whether in a mixer wagon or via Farmlands manufactured dairy blends or pelleted feeds.

Remember that binders are a supportive tool, not a cure. They reduce harm but do not remove the source of contamination. With awareness, proactive feed strategies and targeted binders, farmers can significantly reduce the negative effects of mycotoxins and maintain herd and flock performance. For further advice, contact your local Nutrition Sales Specialist or your local Farmlands store. Expert guidance and regular monitoring will help safeguard productivity and protect farm profitability today.