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For the millions regularly consuming cassava-based foods, the ingestion of sublethal cyanide (CN-) is inevitable. Using oral inorganic CN - solutions, we have replicated the free CN ~ intake levels of Liberian (West African) human groups in a juvenile swine model. We then noted the behavioral changes induced by oral CN - loads of 1.2, 0.7 and 0.4 mg/kg body weight/day for 24 weeks. Timed, daily behavioral determinations were made on a range of performance measures and learning events; CN - treatments were observed to significantly decrease dominance behavior, decrease vocalization, decrease fighting, increase victimization, decrease swine investigations of new environments, decrease aggressive feeding patterns, increase swine distractibility from eating, decrease rooting and water overturning, decrease pica, increase anesthesia recovery time, increase limping and limb stiffness, and increase vomiting and shivering. Exposure to chronic sublethal CN - produced two clear behavioral trends: (1) increasing ambivalence and slower reacting response time to various stimuli and (2) an energy conservation gradient influencing which specific behaviors would be modified first in treated animals. Thyroid hormones T3 and T4 and fasting blood glucose levels were assessed to evaluate energy metabolism while serum thiocyanate (SCN-) was quantified for evidence of oral CN - metabolism. CN ~ treatments diminished T3 and T4 levels but elevated fasting blood glucose values. Serum SCN- was positively correlated with daily CN - intakes. The parallels with human studies are noted and the limitations to extrapolation are identified.