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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #331671
Title: Duration of an induced resistance of sheep to acute poisoning by Crotalaria retusa seeds

Author
item MAIA, LISANKA - Federal University Of Campina Grande
item MACEDO PESSOA, CLARICE - Federal University Of Campina Grande
item RODRIGUES, ANGELICA - Federal University Of Campina Grande
item Colegate, Steven
item DANTAS, ANTONIO FLAVIO - Federal University Of Campina Grande
item MEDEIROS, ROSANE MARIA - Federal University Of Campina Grande
item RIET-CORREA, FRANKLIN - Federal University Of Campina Grande

Submitted to: Electronic Publication
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2013
Publication Date: 6/1/2014
Publication URL: http://handle.nal.usda.gov/10113/63037
Citation: Maia, L.A., Macedo Pessoa, C.R., Rodrigues, A.F., Colegate, S.M., Dantas, A.M., Medeiros, R.T., Riet-Correa, F. 2014. Duration of an induced resistance of sheep to acute poisoning by Crotalaria retusa seeds. Ciência Rural. 44(6):1054-1059.

Interpretive Summary: In northeastern Brazil, spontaneous ingestion of Crotalaria retusa L. has been diagnosed as a cause of chronic liver fibrosis and megalocytosis in horses, and acute liver necrosis in sheep. The aim of this study was to determine the duration of the resistance after the end of the ingestion of non-toxic doses of Crotalaria retusa seeds. Ten sheep were divided into 3 groups of 3 animals each and a control group with 1 sheep. To induce resistance, sheep in groups 1, 2, and 3 received 20 daily doses of 2g/kg of C. retusea seeds, followed by 7 daily doses of 4g/kg. To determine the duration of resistance the sheep in groups 1, 2 and 3 were challenged orally, 3, 7 and 15 days, respectively, after receiving their last dose of 4g/kg, with a single dose of 5g/kg. Sheep of groups 1 and 2 did not develop overt signs of poisoning. Two sheep of group 3, challenged 15 days after the end of the resistance induction period, showed signs of acute poisoning and died. These results sugges that the induced resistance of sheep to acute poisoning by C. retusa seeds is of short duration, from 7 to 15 days.

Technical Abstract: The aim of this study was to determine the duration of the resistance after the end of the ingestion of non-toxic doses of Crotalaria retusa seeds. Ten sheep were divided into 3 groups of 3 animals each and a control group with 1 sheep. To induce resistance, sheep in groups 1, 2, and 3 received 20 daily doses of 2g/kg of C. retusea seeds, followed by 7 daily doses of 4g/kg. To determine the duration of resistance the sheep in groups 1, 2 and 3 were challenged orally, 3, 7 and 15 days, respectively, after receiving their last dose of 4g/kg, with a single dose of 5g/kg. Sheep of groups 1 and 2 did not develop overt signs of poisoning. Two sheep of group 3, challenged 15 days after the end of the resistance induction period, showed signs of acute poisoning and died. These results sugges that the induced resistance of sheep to acute poisoning by C. retusa seeds is of short duration, from 7 to 15 days.