Molds – more specifically the mycotoxins they produce – can have a significant impact on dairy cattle performance, especially in young calves. That’s because rumen microorganisms in adult dairy cattle act to break down certain mycotoxins, making them less harmful to the animal. Young calves with undeveloped rumens don’t have that line of protection.
Most molds thrive in high levels of moisture. However, aflatoxin, produced by the Aspergillus mold, thrives in periods of excessive heat and drought. The toxin, a concern this year due to the summer’s drought, can deliver a huge blow to a calf as it damages the liver and subsequently the young animal’s immune system. Damage to the calf’s immune system now will have lasting impacts throughout its life.
Source: Vita Plus Starting Strong Calf Care E-News, October 2012