14 October 2014

3 minute read

Everyone in the cattle industry seems to suddenly be talking about mycotoxins, according to Charlie Maclaren, cattle nutritionist at the National Beef Association.

He advises UK farmers that Zealalenone is most prevalent this year in forages, grains and straw and that beef farmers may have a harder time in catching cases early. 

The following is a discussion of what to look for this winter and a break down of advice on what to expect from wet, spoiled feed. 

What are Mycotoxins?

In very simple terms; they are the waste product of Fungi, they are not a living organism.

Where do they come from?

These fungi are found naturally on grasses, straw and most living plant life, and are found throughout the growing season.

How to identify Mycotoxins

Mycotoxins are microscopic, and cannot be seen in forage so it is impossible to identify them with the naked eye, writes Mr Maclaren. However, you will be able to spot tell-tale signs that the forage been eaten contains Mycotoxins by watching the cattle.

If you have milking dairy cows the signs are easier to spot; a sudden drop in milk being the most obvious, or cows not achieving expected milk yield. In the main, these symptoms affect newly calved cows more aggressively, resulting in very loose dung and a rapid loss in weight.

These same symptoms will affect beef cows, causing a mixture of calving problems including still born calves, and a variety of other problems all connected with the animal’s immune system. These problems will show themselves in many different forms.

“It is worth noting,” says Charlie, “that a suckler cow’s diet is based predominately on silage unlike the modern dairy cow so the effects can be even more severe.”

This year Zealalenone is the most prevalent Mycotoxin and is being found in forages, barley and straw. The clinical signs are:

• Abortions
• Decreased embryo survival
• Infertility and mammary gland enlargement of virgin heifers
• Oedema and hypertrophy of the genitalia in pre-pubertal females (Water retention)
• Vaginitis (swollen)
• Vaginal secretions (Discharge)
• Feminisation of young males (Tastical infection)
• Infertility of young males

Ways to Confirm You Have Mycotoxin Issues

Until now testing for Mycotoxins has been expensive and tests were never terribly effective as there are hundreds of different Mycotoxin strains and you had to state which toxin you wanted the lab to look for.

Now there is a simple test which will test for the two most commonly found toxins, Zearalenone and Deoxynivalenol, commonly known as Zon and Don.

This can be completed when sampling your silage for feed value or at any other time with a pit-face sample. This method highlights the potential problem before it becomes one.

The other method, commonly used by dairy farmers is to add a Mycotoxin binder to the cow’s diet at 50gms per day. Within a few days you will see usually an increase in milk and a firming of the dung.

To Conclude Charlie said: “It is so important that we get in front of these toxins as if you try to play catch-up you will be too late.”

The common effects of Mycotoxins are:

• Variable feed intakes
• Inconsistent milk yield
• Reduced fertility
• Scouring
• Acidosis-type symptoms
• Lethargy
• Impaired immune function/poor response to disease or infections
• Poor rumen function
• Muscle tremors
• Bloody faeces
• Lower leg / teat swelling
• Unsettled cows
• General poor performance without any alternative explanation