Zinc deficiency in pheasant chicks fed practical diets.

A disease syndrome characterized by abnormal feathering and varus deviation of the tarsometatarsus spontaneously occurred in pheasant chicks fed a practical commercially prepared diet. The addition of supplemental Zn to the commercial diet was effective in alleviating the clinical signs, even though the commercial mix had Zn levels that met the published pheasant chick requirement. Supplemental arginine was ineffective in reducing the severity of the clinical signs. Also, when the diet was mixed in a laboratory setting, pheasant chicks did not develop abnormal feathering and leg bones. Clinical signs caused by feeding the commercial mix were not reproduced by altering dietary calcium and phosphorus levels in the laboratory mix. Neither adding a pellet binder nor removing supplemental Zn from the lab mix produced as severe leg and feather deformities as the commercial mix. Thus, unidentified dietary factors are capable of causing a Zn-deficiency syndrome in pheasant chicks fed practical diets with analyzed Zn levels meeting the required levels.