title: Invited review: Efficacy, metabolism, and toxic responses to chlorate salts in food and laboratory animals.
abstract: For over 100 yr, scientists have explored uses of sodium chlorate in agricultural applications. Sodium chlorate is a strong oxidizer, and thus can be very hazardous when not handled accordingly. Nevertheless, late 19th century agriculturists and scientists attempted to exploit the chemical properties of sodium chlorate as an herbicide and food preservative. It is the herbicidal utility that led to subsequent use of sodium chlorate in the agricultural industry since then. However, in 2000, USDA-ARS scientists proposed a new and targeted use of sodium chlorate against enterobacteria in food animal production. Specifically, when orally dosed in to cattle (Bos taurus), swine (Sus scrofa), broilers (Gallus gallus), turkeys (Meleagris gallopavo), and sheep (Ovis aries), chlorate reduced the fecal shedding of common enteropathogens of the Enterobacteriaceae family. Subsequent to this discovery, the efficacy of chlorate salts has been demonstrated in numerous production classes within species. Doses of sodium chlorate as low as 30 mg/kg BW, but typically 50 to 150 mg/kg BW, have been used to demonstrate efficacy against pathogens. Single or short-duration (<3 d) exposures to oral chlorate at concentrations < 150 mg/kg BW have not produced acute toxicity or clinical signs (labored breathing, methemoglobinemia) in food animals. In all species studied to date, the major biotransformation product of chlorate is chloride ion; chlorite is not present in tissues or excreta of chlorate dosed animals. Chlorate is rapidly eliminated in ruminants and nonruminants, primarily in urine; likewise, residual chlorate in tissues depletes rapidly. Application of any new chemical entity to food animal production carries with it a responsibility to understand adverse reactions that intended and nonintended exposures may have in target and (or) nontarget animals and an understanding of the pathways of elimination that occur after exposure. Therefore, the purpose of this review is to summarize the published data regarding the efficacy, metabolism, and toxicology of chlorate salts in target (livestock) and nontarget species.
authors.affiliation: USDA-ARS, Biosciences Research Laboratory, Fargo, ND 58105-2765, USA. david.j.smith@ars.usda.gov
authors.forename: D J
authors.initials: DJ
authors.lastname: Smith
authors.forename: C E
authors.initials: CE
authors.lastname: Oliver
authors.forename: J B
authors.initials: JB
authors.lastname: Taylor
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
mesh_terms: D000820:Animal Diseases / Q000139:chemically induced*; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000830:Animals, Laboratory; D002704:Chlorates / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D005504:Food Analysis; D058751:Livestock
chemical_list: D002704:Chlorates