AGRICULTURAL
The Mycotoxin Risk in
Forage and Silage
RUMINANTS ARE UNIQUE ANIMALS. DUE TO A COMPLEX RUMEN SYSTEM, THESE
ANIMALS ARE ABLE TO DERIVE ENERGY AND PROTEIN FROM FORAGE THAT MOST
LIVESTOCK CANNOT EVEN DIGEST PROPERLY. FORAGE HAS THE ADVANTAGE OF BEING
INEXPENSIVE RELATIVE TO OTHER FEED TYPES, BUT WE NEED TO BE AWARE OF THE
MYCOTOXINS THAT THEY CAN CONTAIN.
By Dr. Timothy Jenkins
Development Scientist, BIOMIN
Not just in grains
M
ycotoxins are toxic secondary
metabolites produced by fungi
and they have a huge impact on
the animal industry in respect of health
costs and reduced performance. People
often associate mycotoxins with grains.
This is true, but a comprehensive ration
contains some grain, roughage and often
corn silage as well. Mycotoxins that are
in the grain will generally remain in the
silage. Mycotoxins can be produced in
other parts of the plant as well. These
include some of the Fusarium fungi
mycotoxins that are common in grain
e.g. deoxynivalenol (DON, a concern for
gut health and disease susceptibility),
zearalenone (ZEN, a concern for
reproduction) and fumonisins (FUM,
a further concern for gut health). Little
known Fusarium mycotoxins such as
culmorin compounds and moniliformin
can also be present. There is evidence
that some of these other compounds
exacerbate the effect of DON on animals.
the effect of TeA on ruminants, but it is a
protein synthesis inhibitor and is known to
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Forage can also contain mycotoxins
from other fungi growing in or on plants.
Tenuazonic acid (TeA) produced by fungi
such as Alternaria and Phoma is often
present. A common Phoma disease (black
stem) on forage sorghum means that this
particularly has a frequency of high TeA
contamination. Not much is known about
Figure 1. Aspergillus fumigatus is
one of the most common mycotoxin-
producing silage molds. It can
commonly produce gliotoxin and can
infect the lungs or digestive system
of immunocompromised animals. It
may contribute to heamorrhagic bowel
syndrome (HBS).
SENWES SCENARIO | AUTUMN 2019
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