Provisions for ochratoxin A deoxynivalenol zearalenone fumonisin Bi B2 and T2 and HT2 toxins in feeds

At the request of the Commission the EFSA adopted opinions on the mycotoxins deoxynivalenol on 2 June 2004 (34), zearalenone on 28 July 2004 (35), ochratoxin A on 22 September 2004 (36), and fumonisins on 22 June 2005 (37).

Deoxynivalenol

Deoxynivalenol has toxic effects in humans and all other animal species investigated thus far. Species sensitivity varies considerably, but pigs are generally recognized as the most sensitive animal species. The initial adverse effect observed after deoxynivalenol exposure is reduced feed intake. At higher toxin concentrations vomiting and feed refusal occur. These effects lead to reduced body weight gain, particularly in growing animals. Deoxynivalenol also reduces immune response. The lowest reported levels of deoxynivalenol in feeds with a negative effect on feed intake for pigs range from 0.35 to 0.9 ^g/g. With respect to other animal species, healthy ruminants tolerate several mg of deoxynivalenol per kg of feed. Poultry are less sensitive than pigs to the effects of deoxynivalenol on feed intake and weight gain, but the data do not suffice to estimate a no effect level. Other animal species, including rabbits, horses, cats and dogs, all seem to have a higher tolerance to deoxynivalenol than do pigs.

Deoxynivalenol is metabolized rapidly in animals and carry over to edible tissues, milk and eggs is very low. Thus, animal-derived foods contribute marginally, if at all, to total human exposure to deoxynivalenol.

Zearalenone

The most prominent effects of zearalenone result from its interaction with estrogen receptors resulting in apparent hyper-estrogenism, including reduced fertility. Pigs generally are considered the animal species most sensitive to zearalenone, with boars less sensitive than sows. Limited experimental studies indicate that sheep are the next most sensitive to the adverse effects of zearalenone, whilst cattle are relatively less sensitive. Poultry (chickens and turkeys) are the least sensitive to the hormonal effects of zearalenone. No reliable data are available for other species such as rabbits, horses, cats and dogs.

Zearalenone deposition in meat and other edible tissues is limited, and the transmission rate into milk and eggs is low. Thus, animal-derived foods are expected to contribute only marginally to the total human exposure to zearalenone, with the bulk of the exposure expected from cereals and grain products.

Ochratoxin A

Pigs are considered the most sensitive farm animal species to the nephrotoxicity of ochratoxin A. No no-observed-effect-level (NOEL) can be established, but based on effects on renal (diagnostic) enzyme levels and kidney function, a dietary concentration of 0.2 ^g/g is considered the lowest-observed-effect-level (LOEL). Chickens also are a sensitive species, and ochratoxin A is assumed to be the most important cause of poultry nephropathy. Ruminants are less sensitive to ochratoxin A than are monogastric species. This result is consistent with data indicating that prior to absorption, significant microbial degradation of ochratoxin A to the less toxic ochratoxin a occurs in the rumen. Herbivores such as horses, rabbits and related species that rely on caecal rather than ruminal fermentation may absorb intact ochratoxin A in the small intestine and, therefore, are more likely to be sensitive to this toxin than are ruminants. Other monogastric animal species including dogs, cats and fish are expected to be sensitive to renal toxicity and im-munosuppressive effects, as these effects have been observed in all species tested so far.

Ochratoxin A is retained in blood serum and may accumulate in blood, liver and kidney while significantly lower residual levels are found in muscle tissue, fat and milk. Carry-over into eggs occurs with high exposures under experimental conditions. Exposure assessments indicate that food of animal origin contributes only to a minor extent, on average 3% and in populations with dietary preferences < 10%, to human dietary exposure to ochratoxin A.

Fumonisins

Intoxications associated with the occurrence of fumonisins in animal feeds comprise distinct syndromes such as ELEM (equine leukoencephalomalacia) and PPE (porcine pulmonary edema). Fumonisins exhibit toxic effects in all animal species evaluated thus far. Susceptibility varies considerably amongst species, with pigs, rabbits, horses and other Equidae being the most sensitive. Relative to other animal species, adult ruminants are significantly less sensitive than are calves. For broiler chickens the LOEL level is ~2 mg/kg bw/day. Data from ducks, ducklings and turkeys provide no evidence that these species are more sensitive than chickens. Adult ruminants are not sensitive and have a low responsiveness to fumonisins.

Available data on the carry-over of fumonisins from animal feeds into edible tissues, including milk and eggs, indicate that carry-over is limited and that products of animal origin do not contribute substantially to human exposure.

T-2 and HT-2 toxins

Data on the presence of T-2 and HT-2 toxins in products intended for animal feeding are very limited. There also is an urgent need to develop and validate a sensitive analytical method. However, there are indications that the presence of T-2 and HT-2 toxins in products intended for animal feed could be of concern. Therefore, the development of a sensitive analytical method, collection of more occurrence data and more investigations/research into the factors involved in the presence of T-2 and HT-2 toxins in cereals and cereal products, in particular in oats and oat products, is needed.

Based on current scientific knowledge, the lack of reliable data on T-2 and HT-2 toxins, and the large year-to-year variation that occurs in these mycotoxins, the recommended first step is to collect more data on these mycotoxins in different feed materials and feeds.

Recommendations for deoxynivalenol, zearalenone, fumonisins, ochratoxin A and T-2 and HT-2 toxins

Commission Recommendation 2006/576/EC of 17 August 2006 on the presence of deox-ynivalenol, zearalenone, ochratoxin A, T-2 and HT-2 toxins and fumonisins in products for animal feeding (38) provides recommendations for monitoring the presence of these myco-toxins in feed. The Recommendation is based on Article 211 of the Treaty of the European Community that enables the Commission to formulate recommendations on matters dealt

Table 6. Guidance values (pg/g relative to a feed with 12% moisture content) for deox-ynivalenol, zearalenone, ochratoxin A and fumonisins in animal feeds.

Mycotoxin

Product intended for animal feed

Guidance

You Are What You Eat

You Are What You Eat

Nutrition is a matter that people spend their careers learning about and requires volumes of books to explain. My objective is to instruct you how to consume a healthy nutritional diet that aids your body in burning off fat instead of storing it. You do not require overwhelming science to get this.

Get My Free Ebook


Post a comment