Sequential administrations of trifluoroacetate induce tolerance to Palicourea maccgravii, a monofluoroacetate-containing plant, in calves.

Monofluoroacetate (MFA) is considered one of the most toxic substances known. It is found naturally in plants, and causes sudden death syndrome in ruminants. Due to hyperacute evolution of poisoning and the absence of effective treatment, induction of resistance in animals might be the best tool to control MFA poisoning in ruminants. The objective of this study was to promote resistance in cattle against the toxic effects of MFA through its degradation by the ruminal microbiota after the administration of sodium trifluoroacetate (TFA). Ten calves were distributed into two groups: control group (n = 3) and treated group (n = 7). The calves in the treated group received 0.1 mg/kg live weight of TFA, whereas, those in the control group received water; both for 28 consecutive days. The calves were subjected to daily clinical evaluation and weekly blood biochemical determination to identify any signs of poisoning. After 28 d of administration of TFA or water, 2.0 g/kg body weight of Palicourea marcgravii leaves (containing 0.15% MFA) were administered using a stomach tube to determine the occurrence of resistance. The administration of TFA did not induce any clinical or biochemical changes in blood. The administration of P. marcgravii induced clinical changes in the calves of control group, but there was no change in the calves of the treated group. In conclusion, the administration of TFA to cattle can induce effective resistance against MFA poisoning.