Cyanide in garri. 2. Assessment of some aspects of the nutrition, biochemistry and haematology of the rats fed garri containing varying residual cyanide levels

Abstract

Forty-eight weanling albino rats were used to investigate the dietary implications of the residual cyanide levels of garri using performance, nitrogen balance, relative organ weights, serum and urinary thiocyanate and some haematological variables as the response criteria. The experimental rats showed no outward signs of toxicity. However, rats fed cyanide-containing garri diets had significantly (P ≤ 0.05) slower rates of growth than the controls, and fermentation of cassava improved the utilization of the diets as shown by the enhanced values of feed efficiency, ‘operative’ protein efficiency ratio and biological value with increasing fermentation time. Serum and urinary thiocyanate levels were significantly (P ≤ 0.001) higher in the rats fed garri diets than in the corn starch controls. Regression analysis showed a significant (P ≤ 0.01) positive correlation (r = 0.97) between urinary thiocyanate levels and the residual cyanide content of garri. The haematological variables studied showed no consistent trends related to dietary treatments. The need was emphasised for further tests to determine other underlying cause(s) of the sporadic cases of acute garri intoxication reported in humans.