Induction and transfer of resistance to poisoning by Amorimia pubiflora in sheep whith non-toxic dosis of the plant and ruminal content/Inducao e transferencia de resistencia a intoxicacao por Amorimia pubiflora em ovinos com doses nao toxicas de planta e conteudo ruminal

Amorimia pubiflora (Malpighiaceae), which contains sodium monofluoroacetate (MFA) is the main cause of "sudden death in cattle in the Brazilian state of Mato Grosso. This research investigated the induction of resistance to the poisoning in sheep by the continuous administration of non-toxic doses of the plant and also the possibility to transfer this resistance to other sheep by the transfaunation of ruminal fluid. For this a group of four sheep (Gl) received daily doses of 0.5g [kg.sup.-1] for 20 days and after an interval of 15 days were challenged with three daily doses of 1g [kg.sup.-1] for 3 days. Also the transfer of resistance to A. pubiflora poisoning was evaluated by transfaunation of rumen fluid (100ml for 10 days) from Gl sheep to five sheep (G2), followed by challenge with the dose of 1g kg- for 3 days (G2D2) and after a three-day interval they received a single dose of 3g [kg.sup.-1] (G2D3). The degree of resistance was evaluated by monitoring the onset of clinical signs, heart rate, and outcome of the poisoning compared with the control groups, which were challenged with three daily doses of 1g [kg.sup.-1] (G3) and with a single dose of 3g [kg.sup.-1] (G4). Clinical parameters evaluated in Groups G1 and G2 were significantly less pronounced than those observed in G3 and G4 (control) (P