Pigs to Pork
NUTRITION
Cooperative Extension Service PURDUE UNIVERSITY Lafayette, Indiana
Feeding Moldy Corn to Swine
John E. Tuite and Martin Stob, Botany and Plant Pathology and Animal Sciences Departments
AS-384 Aug. 1968
The Problem
Infection of corn by molds, prior to harvest or in storage, reduces its value as a cash crop or as feed for livestock. The swine producer who discovers that the corn which he intended to feed is moldy faces three problems: (1) reduced feed efficiency and slower gains because of a loss of nutrients in the grain, (2) refusal or reduced intake by the hogs to eat the corn because of the severity of the infection or because of the production of substances which makes the grain unpalatable, or (3) reduced performance of the hogs because of the production of compounds by the molds which are detrimental or toxic to the hogs.
The seriousness of the moldy corn problem depends largely on the kind of mold involved, how much of it is present, and what the species and age of the animals being fed. iMany thousands of bushels of infected grain are fed each year without causing any obvious clinical problems. However, recent research suggests that at least three specific molds tnay cause special problems to Indiana swine producers when they feed corn infected with these molds. There is some indication that there may be other molds which are potentially troublesome.
The Three Specific Molds
Aspergillus flavus. This is a yellow mold, fairly common in grain, which primarily affects stored grain and is rarely found in freshly harvested corn. This mold
requires seed moistures of 16 per cent or above and fairly high temperatures for growth. Large quantities of a very powerful liver toxin and cancer producer are produced by this mold at about 93°F. and high moisture This toxin has caused the death of thousands of turkey poults and is toxic but not necessarily lethal to hogs. Thirty parts per billion (sometimes less) of this toxin in grain may cause sickness in animals.
Penicillium molds. These molds are usually blue or green in color and are very commonly found in stored grain but only occasionally in unharvested corn. These molds, as well as others, cause "blue eye" of stored corn. Penicillium molds have not been incriminated in livestock diseases in Indiana, but some species of this mold are known to be toxic to poultry and mice. More research is required to determine their effects on livestock.
Gibberella zeae. Tins fungus can attack corn both in the field and in stored high moisture corn, and may produce several different substances, any of which may cause problems in swine. The type of compound or substance produced depends on the conditions in which the mold is grown. The three known factors which are produced by the Gib fungus are:
(1) The Refusal Factor - This substance is produced by the mold on the corn ears in the field, and it is not produced in storage. Cool and moist weather at silking time favors growth of the mold and the production of this substance. Infection can be identified by the