The development of molds in both forage and stored grain often goes unnoticed throughout the feeding process. There are various forms, color and locations of mold development. However, moisture content, temperature and high humidity provide an excellent environment for mold development within stored feeds. There are differences in opinions relating to the effect of molds on animal production. However, there have been numerous incidences where the mold or mycotoxin levels have caused digestive, reproductive, and reduced production in the form of both growth and milk.
Calves are generally more sensitive to feed contamination than adult cattle.
In affected calves, some cases have revealed severe straining and prolapses. Liver damage has been associated when high levels of aflatoxin have been fed in finishing rations. Feeding high levels of aflatoxin may also reduce the immune function, resulting in susceptibility to other diseases. Depending on the feed containing the mycotoxin, rations can usually be formulated to meet the suggested feeding levels. Forages containing mycotoxin are the hardest to work with since forages make up a large percent of the ruminant diet.