title: Predicting perchlorate exposure in milk from concentrations in dairy feed.
abstract: Perchlorate has been detected in U.S. milk samples from many different states. Applying data from a recently reported 9-week experiment in which 16 Holstein dairy cows were administered perchlorate allowed us to derive an equation for the dose-response relationship between perchlorate concentrations in feed/drinking water and its appearance in milk. Examination of background concentrations of perchlorate in the total mixed ration (TMR) fed in addition to the variable dose supplied to treated cows as a ruminal infusate revealed that cows receive significant and variable exposure to perchlorate from the TMR. Weekly examination of the TMR disclosed that a change in ingredients midway through the experiment caused a significant (78%) change in TMR perchlorate concentration. Analyses of the ingredients comprising the TMR revealed that 41.9% of the perchlorate came from corn silage, 22.9% came from alfalfa hay and 11.7% was supplied by sudan grass. Finally, USDA Food and Nutrition Survey data on fluid milk consumption were used to predict potential human exposure from milk that contained concentrations of perchlorate observed in our previous dosing study. The study suggests that reducing perchlorate concentration in dairy feed may reduce perchlorate concentrations in milk as well as the potential to reduce human exposure to perchlorate in milk.
authors: Environmental Management and Byproduct Utilization Laboratory, USDA, Agricultural Research Service, Beltsville, Maryland 20715, USA. clifford.rice@ars.usda.gov
authors: Clifford P
authors: CP
authors: Rice
authors: Ransom L
authors: RL
authors: Baldwin Vi
authors: Linda C
authors: LC
authors: Abbott
authors: Cathleen J
authors: CJ
authors: Hapeman
authors: Anthony V
authors: AV
authors: Capuco
authors: Anh
authors: A
authors: Le
authors: Krystyna
authors: K
authors: Bialek-Kalinski
authors: Douglas D
authors: DD
authors: Bannerman
authors: William R
authors: WR
authors: Hare
authors: Max J
authors: MJ
authors: Paape
authors: Gregory W
authors: GW
authors: McCarty
authors: Adam C
authors: AC
authors: Kauf
authors: Ali M
authors: AM
authors: Sadeghi
authors: James L
authors: JL
authors: Starr
authors: Laura L
authors: LL
authors: McConnell
authors: Curtis P
authors: CP
authors: Van Tassell
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle; D004781:Environmental Exposure; D005260:Female; D005506:Food Contamination / Q000032:analysis; D006801:Humans; D008892:Milk / Q000737:chemistry*; D010472:Perchlorates / Q000032:analysis*
chemical_list: D010472:Perchlorates; C494474:perchlorate