MYCOTOXINS ISSUE 17 NEW.qxd_Jerkins feature.qxd 05/08/2013 17:37 Page 2
MYCOTOXINS
Choose haylage with caution, as the integrity of the wrapping and other details can encourage mycotoxin contamination
dependent. There has also been a suggestion that mycotoxin contamination of feed could contribute to colic in some instances, although the evidence for this is not strong, as there are many other feedrelated factors that are equally if not more relevant. Prevalence and relevance to horses The risk of mycotoxicosis in racehorses remains unanswerable at the current time, as we do not know how widespread the contamination of forage, feed, or bedding is, or what the clinical relevance of lowgrade mycotoxin intake is to health and performance in racehorses. This is because there is an absence of any large scale surveys of mycotoxin contamination within the racing environment. A small survey of five racing stables in Ireland was undertaken by the Irish Equine Centre and revealed that a high proportion of hay and haylage was contaminated with molds and mycotoxin (see table 2). Samples of coarse mix, oats, and pelleted feed revealed a much lower level of mold and mycotoxin contamination, with the pelleted feed having the lowest content. However, this was a small sample and certainly my feeling is that the haylage results should be viewed with caution, as no details were provided as to the quality of the haylage sampled, in terms of the integrity of the wrapping and
fermentative status or the stability of the product. A large scale survey of mycotoxin contamination of concentrate feed ingredients including maize, soyabean meal, wheat bran, and rice bran was carried out over two years in the European, Mediterranean, and Asian-Pacific markets. Analysis of 2,753 resultant samples revealed that over 50% of the European samples and 30% of the Asian-Pacific samples were contaminated with one or more mycotoxins. While I would say that the presence of
mycotoxins in some forage, feed, bedding, and stable environments cannot be disputed, conclusions on its true impact on health and performance cannot yet be made. However, from both a manufacturer’s and a trainer’s perspective, at this stage our efforts should perhaps be targeted at reducing the overall risk of mycotoxin exposure in horses in training through a variety of methods. Management strategies Unfortunately, mycotoxins are relatively resistant to chemical or thermal treatment
Table 2: Survey of feed and forage samples in Ireland (Buckley 2007) Irish hay
No. sampled 62
% containing pathogenic fungi 50%
Haylage
54
37%
Canadian hay
63
13%
Coarse mix
38
13%
Oats
26
8%
Pelleted feed
51
4%
Fungi Isolated Aspergillus fumagatus Aspergillus niger Aspergillus flavus Aspergillus fumagatus Aspergillus niger Aspergillus flavus Aspergillus fumagatus Aspergillus niger Aspergillus flavus Aspergillus niger Aspergillus flavus Fusarium Aspergillus niger Aspergillus flavus Aspergillus flavus
Associated mycotoxin Zearalenone
Zearalenone Zearalenone Zearalenone Ochratoxin T2 Toxin Fumonisin T2 Toxin Zearalenone T2 Toxin
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