[Chronic zinc-bacitracin toxicity in chickens].

The administration of zink-bacitracin, mainly bacipharmin, at rates of 300 mg per kg with the feed did not produce toxic effects in birds: there were no changes in the general condition and the blood picture, the activity of SGPT and SGOT, the blood level of sugar, and the microstructure of the viscera over a period of 90 days. However, doses of 1000 mg/kg of the preparation given with the feed to chickens led to sporadic cases of slightly expressed karyopycnosis in the renal tubules. Established was a growth-stimulating effect. By the end of the experimental period the relaive weight of the adrenal glands, kidneys, liver, and heart in the treated birds was lower in most of the cases as compared with the weight of the same organs in the control birds.