1. Determine the stability and chemical fate of chlorate in mixed urine-feces from feedlot
2. Determine the activity of chlorate salts against E. coli O157:H7 in mixed urine-feces. <P>
3. Determine the stability and chemical fate of chlorate in a simulated (anaerobic) lagoon and in
aerobic compost systems fortified with manure from feedlot cattle. <P>
4. Determine ruminal and fecal microbial species responsible for the microbial reduction of
chlorate not associated with pathogen elimination.
Findings: Chlorate salts are being developed as a feed additive to reduce the numbers of harmful bacteria in live cattle. A series of studies was conducted to determine whether chlorate would also reduce the populations of harmful bacteria in cattle wastes (a mixture of urine and feces) and to determine the fate of chlorate after excretion from cattle. Chlorate salts present in manure had no significant effects on two harmful bacterial species, E. coli O157:H7 and Salmonella Typhimurium, probably because chlorate was very rapidly degraded and because relatively low concentrations of chlorate salts were used relative to concentrations that have been shown to kill harmful bacteria in live animals. Chlorate degradation was slowest with low temperatures (5 °C) and the fastest at the highest temperatures (30 °C) tested; nevertheless, even at cool temperatures chlorate degradation occurred in significant quantities. From an environmental standpoint, chlorate use in feedlot cattle would likely have minimal impacts because any chlorate that escaped degradation on the feedlot floor would be degraded in lagoon systems. Collectively our results suggest that the use of chlorate as a food safety tool would be environmentally friendly.