2013 harvest hit hard by mycotoxin contamination

By Roger Abbott

Producers and feed manufacturers have been urged to take steps to manage the storage of their feed ingredients more carefully this year to limit mould growth and combat the annual international mycotoxin levels challenge.

This follows a comprehensive summer harvest survey into the mycotoxin challenges facing producers and feed manufacturers across Europe and North America this year.

Conducted by Alltech, the survey evaluated wheat and maize crops across 14 countries in Europe, along with a number of states in the US and Canada. The company analysed 83 samples of wheat and 24 samples of maize from this year’s harvest for 38 mycotoxins using UPLC-MS/MS technology (Alltech’s 37+ Programme), which gives it the ability to take a more in-depth look at the mycotoxin contamination within ingredients or finished feeds.

It has revealed a continued risk of mycotoxins in maize and wheat, which is expected to lead to lower feed quality and reduced performance across the board, so action is necessary. While results in some areas were similar to those found last year, the situation had worsened in other regions and the survey illustrates the continued need for both producers and feed manufactures to remain on full alert.

“A key “take-home” message from this survey is that 99% of the grain samples collected contained mycotoxins and 83% of these samples contained multiple mycotoxins,” said Nick Adams, global sales director of Alltech’s mycotoxin management team.

Inherent risk

“The presence of mycotoxins is an inherent risk, which producers and feed manufactures must continue to manage to ensure that they can get the best results possible out of their feed and their livestock,” he said, warning that the potential impact of this year’s survey results on both animal health and production needed to be monitored carefully.

In European and Canadian wheat, Type B Trichothecenes (DON group) dominated the mycotoxin mix, while in maize aflatoxins and fumonisins were seen at greater levels, alongside other groups such as Type B Trichothecenes, he said.

In Northern Europe, all but one sample contained multiple mycotoxins and Type B Trichothecenes were at high risk in one third of the samples. Combinations with other mycotoxins at lower levels increased the challenge and the survey found that the risk equivalent quantity (REQ) was generated at ‘high risk’ for pigs and ‘caution’ for ruminants. ‘Caution’ was also advised for all poultry.

The survey also found a high level of multiple mycotoxins in Eastern Europe, with aflatoxins posing a risk to most species.

The REQ there was generated at ‘high risk’ for pigs and ‘caution’ for ruminants and poultry.

Concentration 18 times greater

Meanwhile in southwest Europe, particularly high levels of Type B Trichothecenes and Fumonisins were found, with one sample containing Fumonisins at a concentration 18 times greater than the EU average. The REQ was generated there at ‘high risk’ for pigs, ruminants and all poultry. This ‘large number’ of different mycotoxin families throughout Europe in particular, could contribute to a lowering of feed quality across the region, warned Mr Adams.

Asked what had gone wrong this year, he could not point to anything specific, but explained that the amount of mould growing on the plant in a field and the amount of mycotoxin produced by that mould were affected by a number of different factors.

“This includes everything from seed variety and tillage practices, as well as weather variations, such as the temperatures and the level of precipitation. Therefore, the presence of moulds and mycotoxins is, in fact, something that we should consider as being far more natural and normal than we perhaps give it credit for,” said Mr Adams.

“However, it is important to note that current levels of contamination largely reflect mycotoxin growth before harvest. Subsequent storage of feed often contributes further to the mycotoxin load, by providing warm and moist conditions for mould growth.”

Feed management

Looking at ways to limit the potential damage to feed quality this year, Mr Adams said that ongoing feed management was the greatest tool producers and feed manufacturers had to minimise further challenges. He encouraged them to test feed ingredients for mycotoxin contamination in order to identify certain commodities or batches that might be more heavily contaminated so they could alter the diet formulation accordingly.

They should also take steps to manage the storage of ingredients in a way that would limit further growth of mould and the production of mycotoxins.

This could be achieved through a systematic audit, such as the one developed by Alltech, which was based on HACCP principles, to identify the critical control points that impacted mycotoxin production/risk on the farm, or at the feedmill.

“These critical points act as triggers for action, so when some challenges are discovered during the audit, action can be implemented rapidly to better manage an existing mycotoxin challenge and reduce the chance of further contamination,” said Mr Adams. “Producers and feed manufacturers can also use a broad spectrum adsorbent to reduce the total risk to animal health and performance associated with those multiple mycotoxins that do make it into the finished feed”, he added.

As far as action to prevent a similar situation next year was concerned, Mr Adams pointed out that good agricultural practices were always the basis of minimising any stress that could lead to mould growth and mycotoxin contamination on a growing plant. “That said, however, when you look at the risk models that have been developed in this area, one can’t help noticing that climatic conditions play a large role in the development of moulds and mycotoxins and there is not much anybody can do about that.

Impact on animal health

Summing it all up and looking at the possible impact of the potential mycotoxin challenge on animal health and performance this year and in the future, Mr Adams said that speakers at his company’s European Mycotoxin Management Summit recently pointed out that the challenges of feeding low to medium levels of mycotoxins were the same for all species.

“The speakers, included Dr Soren Thielsen, Pedro Caramona and Dr Tugrul Durali, as well as Dr Julia Dvorska, agreed that at these low to moderate but common mycotoxin levels, the animals may reduce their feed intake, which could lead to slower body weight gain and, therefore, may increase the number of days to market,” said Mr Adams.

“They could also show a higher level of gut disorders, including fibre digestion, or diarrhoea, and be more susceptible to diseases, while also showing less response to health treatments due to their weakened immune systems.

“The scenario being outlined by the results from the latest harvest survey point toward these more subtle symptoms, such as reduced feed intake and efficiency, as well as reduced immunity, rather than the acute responses one often notices when the animals consume high levels of mycotoxins. “These symptoms of chronic exposure may not be easily observed in contrast to the acute responses seen when animals consume high levels of mycotoxins, so it is important that producers maintain a close watch on all their livestock so that they can spot problems and be ready to take action to remedy the situation if necessary, he added.

Source: AllAboutFeed magazine Vol 21 nr 10, 2013