Submitted to: Farm Progress Companies and their Family of Farm Magazines
Publication Type: Popular Publication
Publication Acceptance Date: October 15, 1998
Publication Date: N/A
Technical Abstract: The GI tract of animals and man is an ideal habitat for the growth of bacteria. Most gut bacteria are harmless types, but some strains of E. coli can cause acute illness and even death. E. coli senses the acid concentration of its environment. If the growth environment contains little or no acid, the E. coli are easily killed by the acid of gastric juice. If the E. coli is conditioned with small amounts of acid in its growth environment, it becomes extremely acid-resistant, and it is more likely to penetrate the gastric barrier to cause infection. Cattle don't digest starch well and undigested corn often passes through the rumen and small intestines to the colon. Starch that reaches the colon is fermented and this fermentation produces acids that trigger the extreme acid-resistance of E. coli. Cattle fed large amounts of rolled corn had one million acid-resistant E. coli per gram of feces. Acid-resistant E. coli are better adapted to pass through the gastric stomach and cause infection, and even dairy cattle fed moderate amounts of grain (<60%) had 100,000 acid-resistant E. coli.