On the effects of Fusarium toxin contaminated wheat and feed intake level on biotransformation and carry over of deoxynivalenol in dairy cows

Karen Seeling (1) , Sven Dänicke (2) , Hana Valenta (2) , Hans van Egmond (3) , Ronald Schothorst (3) , Peter Lebzien (2) , Margit Schollenberger (4) , Ebrahim Razzazi-Fazeli (5) , A. A. Jekel (3)

1 Federal Agricultural Research Centre (FAL)
2 Institute of Animal Nutrition
3 ARO - Laboratory for Food and Residue Analyses
4 Institute of Animal Nutrition
5 Institute of Nutrition

An experiment was carried out to examine the effects of feeding Fusarium toxin contaminated wheat (8.21 mg deoxynivalenol, DON, and 0.09 mg zearalenone, (ZON), per kg dry matter, DM) at different feed intake levels on biotransformation and carry over of DON in dairy cows. For this purpose, fourteen ruminal and duodenal fistulated dairy cows were fed a diet containing 60 % concentrate with a wheat portion of 55 % (Fusarium toxin contaminated wheat [mycotoxin period] or control wheat [control period]) and ration was completed with maize- and grass silage (50:50) on a DM basis. Daily DON intakes ranged from 16.6 up to 75.6 mg in the mycotoxin period at DM intakes of 5.6 up to 20.5 kg. DON was almost completely biotransformed to de-epoxy DON (94-99 %) independent of the DON/feed intake, and the flow of DON and de-epoxy DON at the duodenum related to DON intake ranged between 12 and 77 % when the Fusarium toxin contaminated wheat was fed. In the serum samples, de-epoxy DON was detected in the range of 4 up to 28 ng/ml in the mycotoxin period, while concentrations of DON were all below the detection limit. The daily excretion of DON and de-epoxy DON in the milk of cows fed the contaminated wheat varied between 1 and 10 µg and 14 and 104 µg, respectively. The total carry over rates as the ratio between daily excretion of DON and de-epoxy DON into milk and DON intake were in the range of 0.0001 up to 0.0002 and 0.0004 up to 0.0024, respectively. Total carry over rates of DON as DON and de-epoxy DON into the milk increased significantly with increasing milk yield. In the urine samples, de-epoxy DON was the predominant substance as compared to DON with a portion of the total DON plus de-epoxy DON concentration up to 96 % when the Fusarium toxin contaminated wheat was fed, whereas the total residues of DON plus de-epoxy DON in faeces ranged between 2 and 18 % of DON intake in the mycotoxin period. The degree of glucuronidation of de-epoxy DON was found to be approximately 100 % in serum. From 33 up to 80 % of DON and from 73 up to 92 % of de-epoxy DON and from 21 up to 92 % of DON and from 86 up to 100 % of de-epoxy DON were glucuronidated in the milk and urine, respectively. It is concluded that DON is very rapidly biotransformed to de-epoxy DON in the rumen and only negligible amounts of DON and de-epoxy DON were transmitted into the milk within the range of 5.6 up to 20.5 kg/d DM intake and milk yields (fat corrected milk, FCM) between 10 and 42 kg/d.

Mots clés: Life Sciences

Karen Seeling, Sven Dänicke, Hana Valenta, Hans van Egmond, Ronald Schothorst, et al.. On the effects of Fusarium toxin contaminated wheat and feed intake level on biotransformation and carry over of deoxynivalenol in dairy cows. Food Additives and Contaminants, 2006, 23 (10), pp.1008-1020. ⟨10.1080/02652030600723245⟩. ⟨hal-00578286⟩