Dennis Dugan of Triple D Dairy in Casa Grande, Ariz., clearly remembers the year 1979. Until then, aflatoxin was relatively unheard of in Arizona. That soon changed when dairy producers there starting feeding cottonseed. Unfortunately, the feedstuff also harbored aflatoxin, which contaminated the milk supply.

Aflatoxin: Lessons from the past“Everybody had aflatoxin in their milk,” Dugan recalls. At the time, there were roughly 150 dairies in the state, so when they had to dump their milk, “it made headlines,” he said during a presentation at the Vita Plus Dairy Summit in early December.

It took six to seven months for milk sales, and consumer trust, to pick back up again.

Flash forward to 2012. More pounds of corn silage started going into Arizona dairy diets than ever before, Dugan says. Aflatoxin showed up again, forcing producers to dump milk for several days late last fall.

“There was almost 4 million pounds of milk dumped,” Dugan said.

His take-home: If your corn has been stressed by drought and you’re feeding 45-50 pounds of corn silage, you’re bound to run into aflatoxin. A lot of you open up that new crop corn silage this month. Be extra vigilant!