title: Short communication: Toxicokinetics of ochratoxin A in dairy ewes and carryover to milk following a single or long-term ingestion of contaminated feed.
abstract: Ruminal microbes have the capacity to inactivate ochratoxins, rendering ruminants less sensitive to this fungal contaminant found in cereal feeds. However, ochratoxin A has been reported in milk surveys. The objective of this study was to assess the toxicokinetics, excretion, and transmission into milk of ochratoxin A using doses similar to those of naturally occurring field contaminations. Six Lacaune dairy ewes in late lactation were separated into 2 groups that received a single dose of contaminated wheat containing 5 or 30 μg of ochratoxin A/kg of body weight. After administration, toxicokinetics and excretion were monitored for 48 h. Subsequently, ewes were administered the corresponding toxin dose daily for 24 d followed by a second toxicokinetics and excretion monitoring period for this long-term exposure. The doses used did not affect production or health of ewes. After a single dose, ochratoxin A and its main metabolite, ochratoxin α, were found in blood 1h postexposure. The maximum blood concentrations of ochratoxin A and α, respectively, were dose dependent and were observed, on average, 6 and 8h after exposure. Long-term exposure increased the maximum concentration of ochratoxin A detected in blood, whereas ochratoxin α was not affected. In contrast, the time to reach the maximum concentration was reduced to 3h for both molecules. Ochratoxins, essentially ochratoxin α, were mainly excreted in feces. Ochratoxin A and α were detected in milk at concentrations that were dose dependent but with a low carryover rate (<0.02%). Chronic administration did not increase the concentration of toxin in milk. Even though ochratoxin A can escape ruminal degradation and traces were found in milk of experimentally exposed ewes, the low carryover of ochratoxin A in milk minimizes the risk to consumers.
authors: INRA, UMR1213 Herbivores, F-63122 Saint-Genès-Champanelle and Clermont Université, VetAgro Sup, UMR Herbivores, BP 10448, F-63000, Clermont-Ferrand, France.
authors: H
authors: H
authors: Boudra
authors: S
authors: S
authors: Saivin
authors: C
authors: C
authors: Buffiere
authors: D P
authors: DP
authors: Morgavi
mesh_terms: D000818:Animals; D001835:Body Weight; D003612:Dairying; D004435:Eating; D005243:Feces / Q000737:chemistry; D005260:Female; D005506:Food Contamination; D007774:Lactation / Q000502:physiology; D008892:Milk / Q000737:chemistry*; D009793:Ochratoxins / Q000032:analysis* / Q000493:pharmacokinetics* / Q000633:toxicity; D012417:Rumen / Q000378:metabolism; D012756:Sheep / Q000502:physiology*; D014908:Triticum / Q000382:microbiology / Q000633:toxicity*
chemical_list: D009793:Ochratoxins; C000426:5-chloro-8-hydroxy-3,4-dihydro-3-methylisocoumarin-7-carboxylic acid
keywords: dairy ewe; milk transfer; mycotoxin; toxicokinetics