|Fox, J - TX A&M UNIVERSITY|
|Carstens, G - TX A&M UNIVERSITY|
|Miller, R - TX A&M UNIVERSITY|
|Jung, Yong Soo|
Submitted to: Beef Cattle Research in Texas
Publication Type: Experiment Station
Publication Acceptance Date: August 10, 2004
Publication Date: August 30, 2004
Citation: Fox, J.T., Anderson, R.C., Carstens, G.E., Miller, R.K., Jung, Y., McReynolds, J.L., Callaway, T.R., Edrington, T.S., Nisbet, D.J. 2004. Effect of nitrate adaptation on the bactericidal activity of an experimental chlorate product against E. coli in cattle. In: 2004 Beef Cattle Research in Texas. College Station, TX: Texas A&M University. p. 113-115. Interpretive Summary: Cattle are natural carriers of pathogenic bacteria such as enterhemorrhagis E. coli and Salmonella. An experimental feed supplement containing a chlorate product developed by the USDA has been shown to kill these enteropathogens and results from studies with chickens and pigs have shown that the ability of the chlorate product to kill these pathogens can be markedly enhanced by first feeding the animals low levels of nitrate. The objective of this study was to examine the effects of such a nitrate adaptation on the ability of the chlorate product to kill E. coli in cattle. Results showed that the chlorate product by itself was indeed effective at reducing E. coli in feces from cattle feed the product but contrary to that observed with chickens and pigs, feeding nitrate prior to feeding the chlorate product did result in enhanced killing of E. coli. Rapid degradation of nitrate in the cattle's first stomach, the rumen, is implicated as the most likely explanation for why feeding nitrate did not result in enhanced E. coli killing in the cattle's feces by the chlorate product. These results more clearly define real world dosing strategies for the experimental chlorate product and thus will help to move this technology towards commercial application and will ultimately help provide a technology that facilitates the production of microbiologically safer beef products for the American consumer.
Technical Abstract: An experimental chlorate product (ECP) developed by the USDA has been shown to have bactericidal effects against enteropathogens such as Escherichia coli. In studies with broilers and pigs, the bactericidal activity of ECP was enhanced by prior adaptation of gastro-intestinal microflora to nitrate. The objective of this study was to examine the effects of nitrate adaptation on the bactericidal activity of ECP against E. coli in Holstein steers. Results indicate that ECP was effective at reducing generic E. coli. However, ECP did not reduce generic E. coli in a dose-dependent manner indicating that the highest ECP dose provided in this study was in excess of that needed to be efficacious. Adapting gastro-intestinal microflora with nitrate prior to feeding ECP did not improve efficacy of ECP against E. coli. Rapid reduction of nitrate in the rumen is implicated as a possible explanation for why adaption to nitrate did not enhance the bactericidal effects of ECP in cattle.