| Abstrakt: |
Further evidence has been obtained of the presence, in crude materials, of unidentified substances, apparently organic in nature, which stimulate growth of chicks fed a purified diet containing soybean protein and adequate quantities of all known vitamins. One of these, found in liver extract, appeared to replace zinc to a great extent or to render it more available. Another factor(s), present in a mixture of distillers’ dried solubles, dried whey and fish solubles, promoted growth of chicks fed a purified diet adequate in zinc. |
