Conditioned food aversion to control poisoning by Ipomoea carnea subsp. fistulosa in goats

Authors: OLIVEIRA, CARLOS - Veterinary Hospital, Federal University Of Campina Grande (UFCG); RIET-CORREA, GABRIELA - Federal University Of Para; TAVARES, CARLA - Federal University Of Para; SOUZA, ELDA - Federal University Of Para; CERQUEIRA, VALIRIA - Federal University Of Para; Pfister, James; Cook, Daniel; RIET-CORREA, FRANKLIN - Veterinary Hospital, Federal University Of Campina Grande (UFCG)

Submitted to: Electronic Publication
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2013
Publication Date: 7/1/2014
Publication URL: https://handle.nal.usda.gov/10113/63002
Citation: Oliveira, C.A., Riet-Correa, G., Tavares, C., Souza, E., Cerqueira, V.D., Pfister, J.A., Cook, D., Riet-Correa, F. 2014. Conditioned food aversion to control poisoning by Ipomoea carnea subsp. fistulosa in goats. Ciencia Rural. 44(7):1240-1245.

Interpretive Summary: Ipomoea carnea is a toxic plant often ingested by livestock in Brazil. Some evidence suggests that animals that begin to feed on swainsonine-containing plants become habituated, and eat the plants compulsively regardless of palatability. Conditioned food aversion can be used in ruminants to avoid eating poisonous plants. Three experiments were conducted to determine if conditioned food aversion was effective in reducing goats’ consumption of I. carnea. In the fi rst experiment, 10 mildly intoxicated goats that had been eating I. carnea were averted using LiCl (175 to 200mg kg-1 body weight). These intoxicated goats did not develop an aversion to I. carnea, demonstrating that the technique is not effective in goats that are already accustomed to consuming the plant. In the second experiment, 14 naïve goats were placed in a pasture with I. carnea, and averted after they ingested the plant. In this group the aversion persisted until the end of the experiment, 2 years and 8 months after the initial aversion. In another experiment, 20 goats were placed in a pasture with I. carnea, and after consuming the plant were averted with LiCl. The averted goats were transferred to Marajo Island and periodically observed over a 2 year period at 2-3 month intervals to determine if they were still averted. The averted goats did not ingest the plant while grazing in the pasture, whereas in 6 neighboring goat farms the prevalence of intoxication from I. carnea poisoning was estimated to be about 40%. These results demonstrated the efficacy of conditioned food aversion to avoid ingestion of I. carnea in formerly naïve goats that had only recently begun to ingest the plant.

Technical Abstract: Ipomoea carnea is a toxic plant often ingested by livestock in Brazil. Three experiments were conducted to determine if conditioned food aversion was effective in reducing goats’ consumption of I. carnea. In the fi rst experiment, 10 mildly intoxicated goats that had been eating I. carnea were averted using LiCl (175 to 200mg kg-1 body weight). These intoxicated goats did not develop an aversion to I. carnea, demonstrating that the technique is not effective in goats that are already accustomed to consuming the plant. In the second experiment, 14 naïve goats were placed in a pasture with I. carnea, and averted after they ingested the plant. In this group the aversion persisted until the end of the experiment, 2 years and 8 months after the initial aversion. In another experiment, 20 goats were placed in a pasture with I. carnea, and after consuming the plant were averted with LiCl. The averted goats were transferred to Marajo Island and periodically observed over a 2 year period at 2-3 month intervals to determine if they were still averted. The averted goats did not ingest the plant while grazing in the pasture, whereas in 6 neighboring goat farms the prevalence of intoxication from I. carnea poisoning was estimated to be about 40%. These results demonstrated the effi cacy of conditioned food aversion to avoid ingestion of I. carnea in formerly naïve goats that had only recently begun to ingest the plant.