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Mycotoxins Threaten Cow Health and Performance in the United Kingdom

With almost 94% of recent TMR samples containing a level of mycotoxin contamination considered high risk to dairy cows, all producers are being advised to consider a mycotoxin assessment to determine the level of threat to their herd.

“In recent samples tested by Alltech, we’re finding very high levels of mycotoxin contamination, particularly from penicillium moulds which develop during storage,” says Louise Clarke, south west technical manager at Alltech.

“This particular type of mould is known to significantly impair rumen function and cause acidosis type symptoms, such as diarrhoea.  Subsequently, production drops, most notably yield and butterfat levels.”

This has been the experience for Andrew Creed, who milks 300 cows at Knapp Farm, West Pennard in Glastonbury.  Mr Creed, who manages the family farm along with his father, recently discovered a mycotoxin problem in the herd which was depressing cow health and productivity.

“The cows just were not milking right, both yield and quality was down.  Additionally, the dung was very loose and some cows were suffering from swollen hocks.  It was quite clear something wasn’t right,” explains Mr Creed.

“The cows are fed a TMR of maize silage, grass silage, soya rape, treated wheat, and straw.  There were no obvious signs of mould in either the maize or silage clamps and we always try to manage our forage well at harvest, in the clamp, and during feeding, to avoid any contamination.  Therefore, I didn’t initially suspect mycotoxins as the culprit.”

However, following an Alltech 37+ test, a significant level of mycotoxin challenge was identified in TMR samples for both the milking and dry cows.

Miss Clarke explains the results: “Higher levels of zearalenones, type A trichothecenes and other penicillium mycotoxins were detected.  These mycotoxins have detrimental effects on rumen and intestinal functions, which can lower feed efficiency, as well as internal organ health and immunity, which could explain the problems observed by Mr Creed.”

Mycotoxin Binder Introduced

Given the high level of mycotoxins found by the test, coupled with the clinical symptoms, Mr Creed needed to reduce the level of mycotoxin challenge to avoid continued poor health and performance, as well as longer term impacts on key areas such as fertility.  He decided a mycotoxin binder was the best course of action.

“I would always rather prevent the problem at harvest, however despite our best efforts, we have a mycotoxin challenge to deal with this year,” he says.

“With margins low, every input is scrutinised and I wouldn’t have used a binder without proof it’s needed.  However, after just three weeks of including Mycosorb A+ and a live yeast into the diet, I have started to notice an improvement in the cows.”

“Manure consistency has improved significant, changing from a score of 5 to 3.  Butterfat levels have also improved from 3.85 to 3.95% protein is up from 3.3. to 3.4% and yield is rising too.”

“The improvements Mr Creed has noted to date indicate the rumen is recovering from damage caused by mycotoxins,” says Miss Clarke.

“It can take up to nine weeks for the rumen to fully recover and I expect that rumen function and efficiency will continue to improve, which will be reflected in both milk yield and quality.”

“Mr Creed’s experience highlights that even well-managed systems are at risk.” She adds.  “Producers often don’t recognise the threat because mycotoxin producing moulds aren’t always visible to the eye, and associated symptoms in cows can be subtle and non-specific.  While good management at harvest and during feeding can help reduce the threat, cows often face multiple mycotoxin challenges which can be hard to eliminate.”

“I would advise farmers to get an on-farm mycotoxin assessment, which we offer free of charge.  This will identify risk, by looking at areas such as clamp compaction and clamp temperature, along with feeding management and general herd health.”

“If a high level of risk is detected, or clinical symptoms are being seen with no other obvious cause, a full mycotoxin test of the TMR or forage would be recommended.  It’s usual for mycotoxins to be detected in a test, but it’s important to know the type and level, to determine actual risk to cow health and what action is necessary.

“If producers decide to use a mycotoxin binder, it’s important to choose a broad-spectrum product to protect against contamination from multiple mycotoxin species.”

Reproduced with kind permission of British Dairying magazine