INFLUENCE OF MINERAL SUPPLEMENTATION ON 2,3-DIHYDROXYPYRIDINE TOXICITY IN ANGORA-GOATS

To study the effect of mineral supplementation on 2,3-DHP toxicity, 16 mature Angora wethers were randomly allocated to four treatment group s (M, DM, D and C). Two hours after the morning feeding; group M recei ved a mineral mixture of 2 g of Fe-2(SO4)(3) . 7H(2)O, 2 g of MgSO4 . 7H(2)O and 2 g of ZnSO4 . 7H(2)O intraruminally in 80 mt of water; gro up DM received a similar mineral mixture plus 6 g of 2,3-DHP (DHP chel ated with metal ions), group D received 6 g of 2,3-DHP in 80 mt of wat er and group C received 80 mt of water. In group D, two animals died w ithin 24 h of receiving DHP and the other two animals were sacrificed to prevent suffering. Ruminal concentration of DHP was approximately 1 8 X higher in group D than in group DM (2.8 vs. 0.16 mmol L(-1); P < 0 .05) 4 h following treatment. Plasma DHP concentration, 6 h post treat ment, was lower in group DM than in group D (15.2 vs. 85.9 nmol mL(-1) , P < 0.05). Urinary excretion of 2,3-DHP was much faster in group DM than in group D (P < 0.05), Plasma triiodothyronine in group D was low er (110 vs. 211 ng dL(-1); P < 0.05) than in group DM. It appears that mineral supplementation prevented 2,3-DHP toxicity. Faster urinary ex cretion of chelated 2,3-DHP suggests that 2,3-DHP must be chelated to be efficiently transported and cleared by the kidney.