Farmers are being warned to keep their eyes peeled for signs of contamination in feed after sampling has shown high mycotoxin risk levels.
UK-wide sampling carried out by Alltech has shown that 46% of total mixed rations (TMR) produced using spring-summer silage have a moderate to high mycotoxin risk.
“The most common types of mycotoxin found were the Type A Trichothecenes and the Penicilliums,” explains Bob Kendal, North England ruminant manager at Alltech.
“Penicilliums are found in silages and are of particular concern for ruminants. The mould starts life white in colour before developing a blue/grey/green colour and, as the name suggests, can have an antibiotic effect on rumen bacteria.
“This manifests itself as acidosis-like symptoms, dung consistency and sudden drops in milk.
“Type A Trichothecenes includes T-2 toxin which can have a serious effect on the gut of the cow and reduce intakes and performance.”
There are five key signs of mycotoxin, which farmers should look out for:
1. Visible moulds
Mycotoxins are commonly produced by Penicillium, Aspergillus and Fusarium moulds, which can be identified by colour:
- Pink (white to red): Fusarium or field-borne moulds
- Blue-green: Penicillium – typically more storage-related, but can occur in the field in certain weather conditions
- Olive green-yellow: Aspergillus – very common in dry climates.
Any spoiled feed should be regularly removed, so it doesn’t enter the diet.
2. Gastrointestinal problems
If faeces are loose or inconsistent, it signifies a problem with digestion and gut health, which could be a sign of a mycotoxin challenge.
Reduced feed intake affecting yields and body condition scores (BCS) can also be a sign of gastrointestinal issues caused by consumption of mycotoxins.
3. Fatigue and health issues
External indicators of mycotoxin contamination include:
- Swollen hocks
- Arched backs
- Cracks showing separation of hooves from feet.
A lethargic herd could also indicate an intake of fumonisins (from fusarium mould). This will be seen through:
- Longer laying times
- Resistance to standing
- Dull appearance.
4. Milk yield and quality changes
A sudden or temporary milk loss – which is hugely problematic for the farm – could indicate contaminated feed, as could an increased somatic cell count (SCC).
The SCC increase would be caused by mycotoxins suppressing the immune system and making cows more susceptible to disease such as bacterial challenge.
5. Breeding performance
Mycotoxins can have indirect impacts on breeding through other health issues, but some mycotoxins have also been found to be directly linked with cystic ovaries and embryonic mortality. Therefore, unexplained lower pregnancy rates could be a warning sign of a mycotoxin problem.
Action in the case of suspected mycotoxin issue
While mycotoxins are inevitable to some extent and prevention where possible is better than cure, there are measures you can take to reduce their impact.
- Keep an eye on heating in the clamp. Excess air in the clamp will cause temperature to rise, which slows fermentation and aerobic oxidation making spoilage and mycotoxins more likely.
- Get a mycotoxin profile done on silage. Analysis can check for the presence of mycotoxins in feed.
- If mycotoxins are identified, a binder can minimise their effect. This works by binding to mycotoxins so that they are removed from the digestive tract of the animal.
Farmers wishing to raise awareness among farm staff can request a free A4 waterproof protocol poster from the Alltech website for the parlour or farm office.