The Availability of Zinc in Various Compounds to Broad Breasted Bronze Poults

A CONSIDERABLE number of re-cent investigations have concerned the zinc requirement of chickens and tur-keys. This work was stimulated by the re-sults of studies conducted by O'Dell and Savage (1957) and Supplee et al. (1958). Compounds which have been used as zinc sources in the various investigations in-clude zinc carbonate, zinc chloride, zinc oxide, zinc sulfate and certain zinc pro-teinates. A few comparisons have been made, but only one detailed study has been conducted to determine the bio-logical availability of zinc from various sources to chicks and poults. Roberson and Schaible (1958) reported that the zinc in zinc sulfate and zinc chloride was equally available to starting chicks. One-hundred parts per million (ppm.) of zinc from each compound was added to a zinc-deficient, purified diet. This level of supplementary zinc, how-ever, was more than three times the amount required by chicks. No definite conclusions regarding availability can be drawn from these data. Pensack et al. (1958) studied the relative growth-stimu-lating effect of several organic and inor-ganic zinc salts for chicks. Levels of 6, 20