A purified diet for one‐day‐old chicks

In each of four experiments 140 or 160 1‐d‐old broiler chicks were fed for 14 d on diets based on crystalline amino acids and other purified ingredients. The basal diet was a purified diet found suitable for 7‐d‐old chicks. 2. Growth was poorer with the basal diet than with a practical diet and it was not improved by an increase in the concentration of vitamins or supplementation with isolated soy protein, water or liver. 3. An increase in the amount of mineral mixture or of magnesium alone gave a significant improvement in growth, so that it approximated that obtained with the practical diet. Food conversion efficiency was significantly better with the mineral‐supplemented than with the practical diet. 4. The basal purified diet supplemented with magnesium to provide 684 mg Mg per kilogram was satisfactory for the early growth; chicks fed on this diet did not respond to sources of “unidentified factors” such as fresh or freeze‐dried liver and soy‐protein.