Producer > Dairy
Q. 2. What are the symptoms of mycotoxins in your dairy herd?
It's nothing that you can quite put your finger on, but..
- The cows don't seem to be milking quite as well as they should be
- The dung is a little loose and variable
- The butterfat is a bit lower than it could be
- The cell counts have crept up and the fertility seems to be getting worse
(a) Common effects of mycotoxins
- Variable intakes
- Inconsistent milk yield
- Reduced fertility
- Scouring
- Acidosis-type symptoms
- Lethargy
- Impaired immune function
- Poor rumen function
- Muscle tremors
- Bloody faeces
- Lower leg / teat swelling
- Unsettled cows
- General poor performance without any alternative explanation
(b) Are there safe levels of mycotoxins for dairy?
Some of the factors that make diagnosis difficult also contribute to the difficulty of establishing levels of safety. Mycotoxin effects are moderated by factors such as sex, age, duration of exposure and environmental and production stresses.
One area of particular concern is that a low level of several mycotoxins can be more problematic than high levels of an individual mycotoxin, due to a synergistic relationship. So even if the feed samples tested come back as being "low", there may still be an issue.
Partial degradation of certain mycotoxins in the rumen does mean that they are less toxic to cattle than to most other animals, but some of these degradation products can be more toxic than the original mycotoxin.
(c) Are dairy products contaminated when dairy cattle consume mycotoxin contaminated feed?
The majority of human health risk from mycotoxins is from the consumption of contaminated grains and nuts. Several mycotoxins have been shown to occur in the milk of dairy cattle, though concentrations are extremely low. Other than aflatoxin, they are not considered likely human health hazards in milk.
