In Brazil is estimated that poisoning of livestock by sodium monofluoroacetate (MFA) containing plants causes the death of about 500.000 cattle per year. The ruminal inoculation of bacteria that degrade MFA has been proposed as a way to prevent the poisoning. This study aimed to evaluate in goats resistance to the MFA-containing plant Amorimia septentrionalis induced by ruminal inoculation of the bacteria Pigmentiphaga kullae and Ancylobacter dichloromethanicus. Twelve goats, without previous contact with MFA-containing plants, were divided into two groups of six animals each. In group 1, 60ml of a mixture of the two bacteria was inoculated every day for 10 days into each goat. In group 2, the goats did not receive the bacteria. At the 10th day of inoculation, A. septentrionalis began to be administered daily at a dose of 5g/kg body weight to both groups. The administration was interrupted in each goat after first clinical signs of poisoning were observed.. The goats of group 1 showed clinical signs 5.83±2.56 days after the administration of the plant, what differed significantly (p=0.037) from goats of group 2, that showed clinical signs 2.67±0 52 days after the beginning of ingestion. The amount of A. septentrionalis ingested by inoculated goats (28.83±12.97g/kg) to cause clinical sings was significantly greater (p=0.025) than the amount ingested by the non-inoculated (12.03±3.65) goats to cause clinical signs and was also statistically different between the groups. We concluded that the intraruminal administration of Pigmentiphaga kullae and Ancylobacter dichloromethanicus increases the resistance to poisoning by MFA-containing plants.

Amorimia septentrionalis is an important sodium monofluoroacetate (MFA) containing plant that causes sudden death in ruminants in northeastern Brazil. MFA degrading bacteria are being used in the prevention against poisoning by this plant. The aim of this study was to evaluate if goats which had per os received MFA degrading bacteria remained resistant when exposed to natural poisoning by A. septentrionalis. Eighteen goats were randomly distributed into three groups: the goats of Group 1 previously received, during 40 days, a solution containing the bacteria Ralstonia sp. and Burkholderia sp., those goats in the Group 2 received the bacteria Paenibacillus sp. and Cupriavidus sp. and goats from Group 3 did not receive any bacteria. After the administration period, during 60 days, the animals of all groups were released to graze on a one hectare paddock, with significant amount of A. septentrionalis. They were observed daily for the spontaneous consumption of A. septentrionalis leaves and the occurrence of clinical signs of poisoning or sudden death. Goats from all groups consumed significant amounts of A. septentrionalis during the experimental period. Goats that did not receive MFA-degrading bacteria (Group 3) became sick and died from the 25th to the 27th day of the experiment, whereas the goats of the groups that received MFA-degrading bacteria showed only clinical sings when A. septentrionalis regrowth after the 55th day of the experiment. The days elapsed from field observation to death of Group 3 goats (25.5±0.9 days) were significantly lower (p<0.05) than Group 1 (58.6±1.3 days) and Group 2 (57.8±1.5 days). Thus, it can be concluded that administration of MFA degrading bacteria increases the resistance to natural poisoning by A. septentrionalis.