Zinc, Copper and Manganese Toxicities in Turkey Poults and Their Alleviation by EDTA

THE essential nature of zinc (O’Dell and Savage, 1957; Supplee et al., 1958), copper (Elvehjem and Hart, 1929; Savage et al., 1962; Al-Ubaidi and Sullivan, 1963), and manganese (Wilgus et al., 1937; Ringrose et al., 1939; Evans et al., 1942) for poultry has been established. The availability of minerals present in the diet is improved by ethylenediaminetetraacetic acid (EDTA) (Kratzer et al., 1959; Davis et al., 1962). Whether EDTA will make excesses of minerals more available and increase their toxicity is not known. Information regarding the tolerance and toxicities of these minerals and the effect of EDTA on them is needed to further understand chelate function in the animal. Zinc had no deleterious effects on chickens up to 1,000 p.p.m. but was growth depressing at 1,500 p.p.m. and caused severe mortality at 3,000 p.p.m. (Roberson and Schaible, 1960; Tahara et al., 1962). A depression in growth of chicks at 2,000 . . .