What's in your ration?

TL;DR:

• Mycotoxins are byproducts of fungi, which can show up in feeds
• Mycotoxins were fed to beef steers for 21 days at levels that were realistic for a feedlot ration
• The treatment had upregulated pathways associated with oxidative stress and inflammation

What you need to know: Mycotoxins are byproducts of fungi, which can show up in feeds that fungus have made their home. Their presence is not just a red hue or an off-smell, but can also affect an animal's health and performance. For example, these mycotoxins were shown to impact things like the animal's immune system, the repair and function of their cells, and can even be toxic to the liver.

Two common mycotoxins, both produced by a common fungus called Fusarium, were fed to beef steers for 21 days at realistic levels to those fed in a run-of-the-mill feedlot ration. Scientists did this to see how these toxins affected cattle when fed at real-life doses.

When looking internally, after 21 days, the consumption of the mycotoxins appears to have compromised the animal's immune system, and their body was using many of its resources to keep the toxin at bay. Namely, pathways that are associated with oxidative stress and inflammation had been upregulated by the treatment.

Using resources to fight off toxins takes away from the animal's ability to put energy towards growth and marbling. And based on the dosages of the toxins fed, animals consuming mycotoxins at realistic levels can develop side effects that impact their health and performance.

The important asterisk*:

• Only 12 animals were used in this experiment. Which is a limited representation of all cattle–more animals would be preferable.
• Other mycotoxins were present in the feed samples, but they were at negligible levels.

Industry Application: Mycotoxins are not a threat to ignore and may be worth testing for to avoid negative impacts on the performance of your herd. Also, precautions can be taken to prevent the growth of mycotoxins in feedstuffs, like adequately packing the silage pit, harvesting only when the moisture is correct, and using fermentation aids.

Read more about it: Effects of Deoxynivalenol and Fumonisins Fed in Combination to Beef Cattle: Immunotoxicity and Gene Expression.