Toxicity of ochratoxin A and tannic acid to growing chicks.

The effects of ochratoxin A (OA) and tannic acid (TA) on growing chicks were determined. One-day-old male broiler chicks were fed a diet containing the following additives for 26 days: A) none; B) 3.0 ppm OA; C) 1.5% TA; D) 3.0 ppm OA plus 1.5% TA. When compared to the controls, body weights and feed efficiencies were significantly depressed in the OA and TA groups. There was a further depression in body weights and a dramatic depression of feed efficiency in the OA-TA combination group. Pigmentation, as measured by visual shank scores, was reduced in chicks fed OA singly or in combination with TA but was not affected by feeding TA singly. There were no consistent treatment differences in the relative weights of the kidney, gizzard, proventriculus, liver, bursa, or pancreas, although there was a trend toward an elevated relative kidney weight in the groups receiving OA. Serum uric acid levels were significantly elevated in the OA and the OA-TA combination group indicating impaired renal excretory function attributable to OA. Total serum protein levels were significantly depressed in the groups receiving OA, and serum calcium levels were depressed in all treatment groups. Serum phosphorus levels were decreased in the OA and OA-TA groups but were only decreased significantly in the OA group. There were no consistent treatment differences in the hematology and other blood chemistry and mineral values.