Moldy feeds are less palatable and frequently reduce dry matter intake. The reduction in dry matter intake leads to a reduction in nutrients absorbed which in turn reduces weight gain and results in a loss in production. It is not uncommon to see a reduction in performance of 5 to 10 percent when mold is present either forages or grains in the rations. Basically as molds grow and develop they reduce energy from the feeds which in turn requires an adjustment in the ration. Dietary fat especially is reduced in feeds that contain mold.
Molds are difficult to recognize and work with in many circumstances.
Moldy or musty feeds will not always contain mycotoxins that are harmful. Mold spore count frequently underestimates the amount of mold present in the feeds. Also moldy feeds may contain a level of toxin that is not detrimental to the animal consuming it. The effects of molds and mycotoxin in feeds are highly variable. It is impossible to predict the effects that molds or mycotoxin are likely to have in an individual situation.