MYCOTOXINS ▶▶▶


The hidden risks of maize silage


New research shows dairy cows’ vulnerability to established and emerging mycotoxins and sheds light on their prevalence in feed.


BY IGNACIO ARTAVIA, PRODUCT MANAGER, BIOMIN C


ows were long believed to be less susceptible to mycotoxins than other animals. The rumen’s ability to degrade toxins was thought to prevent them from passing into the intestine, where they can lead


to decreased absorption of nutrients, “leaky gut” and a higher risk of infections. Unfortunately, we now know that the ru- men can’t fully manage the threat of mycotoxins, and certain conditions worsen the rumen’s ability to protect the cow. For example, a high dry matter intake leads to a faster passage rate, which reduces the time available for detoxifying these compounds. Additionally, if a cow is experiencing subacute


ruminal acidosis (SARA), the cow will become less capable of degrading toxins, leading to a higher likelihood that they reach the intestine. Mycotoxins in feed can harm animals and decrease produc- tion by depressing the immune system and reducing fertility, inevitably leading to farm inefficiency and economic losses. New research has shed light on just how prevalent mycotox- ins are, particularly in silage, and how damaging they can be to cows’ health without proper testing and management strategies.


Risks from silage Silages comprise 50–70% of a dairy cow’s diet in many parts of the world and can contain a variety of mycotoxins. Ruminants are exposed to many more feedstuffs in their diet (e.g. grains, by-products, etc.) than other farm animals are. The 2019 Bi- omin World Mycotoxin Survey, which analysed more than 21,000 samples in 86 countries, found that 75% of samples


 in the intestine


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4    


• Gut barrier damage • Reduced mucin production • Altered Microbiota composition • Weaken local immune system


LEADING TO


• Decreased digestibility and nutrient uptake


• Immunosupression


3 1 2


Rumen Short Intestine


52


▶DAIRY GLOBAL | Volume 7, No. 3, 2020


PHOTO: WIKIMEDIACOMMONS/TRACTORBOY60


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