AGRICULTURAL
29 | The Mycotoxin Risk
have an effect on the digestive tract wall
in poultry.
Grasses
Specific endophytic fungi such as
Neotyphodium species can grow on the
shoots of some grasses, such as fescue
grasses, and these can produce toxic
ergot alkaloids that can cause tremors
and vasoconstriction, contributing to
heat stress, lameness, mastitis and
reproductive issues. Some grass or cereal
crops also has the risk of ergot fungi
Claviceps species that contain the toxic
alkaloids.
Alfalfa
Alfalfa is another common forage crop
and this can also be contaminated with
deoxynivalenol (DON) and zearalenone
and quite commonly can include some
aflatoxin as well which is the highest
profile mycotoxin issue for dairy cows due
to the milk carry-over of aflatoxin B1. Pay
attention to the storage of forages such as
alfalfa and other hays or straw to reduce
the risk of Aspergillus flavus and relatives
that produce aflatoxins.
Silage
Silage introduces a further dimension
of mycotoxin risk since some additional
fungi can grow in the silage material.
It’s important to avoid the feeding of
noticeably moldy areas of silage since
many of the molds (such as Mucor
hiemalis or Aspergillus fumigatus)
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SENWES SCENARIO | AUTUMN 2019
can cause disease within animals or
humans and many of them (including A.
fumigatus) can produce mycotoxins. A.
fumigatus is one of the most common
silage molds and can produce gliotoxin,
an immunosuppressant, and toxic clavine
compounds related to the ergot alkaloids.
Other common silage molds include
Penicillium roquefortii (that can produce
roquefortine C, patulin and mycophenolic
acid), and Monascus ruber (that can
produce citrinin). In some cases, the main method of
management will be to deal effectively
with DON and related compounds since
the effect of DON on the gut wall can be
to increase the uptake of other mycotoxins
and because some of the emerging
mycotoxins increase the effect of DON,
DON is not able to effectively bound in
the animal so management cannot be
achieved with simple binder technology.
The significance of these individual
silage mold mycotoxins in ruminants
does require more research but there
is enough evidence that moldy silage
is generally detrimental to cattle. In
addition to avoiding the feeding of moldy
silage, it is important to reduce the risk
of silage molds by starting with the right
moisture content of forage (not too dry),
compacting the silage adequately and
covering it air tight as soon as possible.
An effective silage inoculant (Biostabil ®)
is also important for improving the stability
of silage both during ensiling and in the
feeding out phase. Mycotoxin management for ruminants
needs to address a wide range of
mycotoxins that are present in the
grain and forage from the field as well
as mycotoxins produced in storage or
ensiling. Mycofix® addresses these
concerns with a multiple strategy of
adsorption (effective on aflatoxins, ergot
alkaloids and some of the silage mold
mycotoxins), biotransformation (the
unique proven ability to deal with some
of the most common mycotoxins) and
bioprotection to safeguard the vulnerable
cells of the gut wall, liver and immune
system.
Effects in animals For more information, contact Albert van
Rensburg and his team at Biomin South
Africa at 018 468 1455, 018 468 1456 or
083 409 5315, send an email to albert.
[email protected] or visit the
website www.biomin.net . References are
available on request. Follow us on FB:
Biomin South Africa.
Many of the additional mycotoxins present
in forages have a toxic effect on protein
synthesis. This means that, as is the
case in respect of many of the common
mycotoxins, their effects are often seen
on the fast growing cells in the body
that require rapid protein synthesis, thus
the gut wall, liver and immune cells.
Mycotoxin solutions