November 9, 2009
US livestock producers warned on corn feed
US pork and poultry producers who do not test the new corn crop before feeding it are taking a risk this year, as wet harvest conditions this year has resulted in the growth of mould in much of Midwest’s corn crop, said Purdue University experts.
Brian Richert, Purdue Extension swine specialist, said a couple producers have started feeding new crop corn and had near 100-percent feed refusal because of the high vomitoxin levels in the corn.
Pigs will have reduced feed intake when deoxynivalenol (DON) levels are above 2 parts per million and near complete feed refusal when DON levels are at 10 ppm or greater in the complete diet, Richert said.
On the poultry side of things, Todd Applegate, Purdue Extension poultry specialist, said not much is known about the ramifications of Diplodia, but poultry are not as sensitive as pigs are to the toxins produced by Giberella mould.
"From a nutritional standpoint, the lower test weights influence the corn kernel's proportions of the germ versus endosperm, causing amino acid and energy shifts," Applegate said when talking about Diplodia concerns. "If this is not accounted for during diet formulation, it could lead to decreased performance."
Applegate explained that Zearalenone, also found in Giberella infected corn, at fairly high concentrations - up to 800 parts per million - may not cause any production impairments in laying hens.
However, he said that part of the concern may lie in transference of those mycotoxins to the egg, as DON or vomitoxin is known to suppress the immune system in poultry, making them more susceptible to sickness. Levels of DON known to have these effects begin to occur at about 7.5 parts per million, or less.
Diplodia, another mould that has been found widespread in this year's US corn crop, can cause low test weights and is prone to shattering, which creates a lot of fine material, explained Richert.
Diplodia does not produce a known toxin and is safe to feed, but could throw off feed intake due to the mouldiness of corn, he said. Long-term shattering and fine material is a concern during storage, because they increase the susceptibility to other moulds including those that produce aflatoxin or ochratoxin.
