Protein Requirements of Chickens

THE growth rate of chickens is rapid for a period immediately after hatching, followed by a period of decreased growth rate which slowly diminishes as maturity approaches. As pointed out by Heuser and Norris (1930) the first period from six to eight weeks calls for rapid growth and high protein levels. The second period, during which growth is less rapid and the protein can be decreased, extends from the end of the first period to twelve or fourteen weeks. The third period growth is still less rapid and the protein level can again be decreased to some extent from the end of the second period to the end of the growing period. It was shown by Norris and Heuser (1930) that the best growth in chicks was obtained the first eight weeks after hatching with a ration that contained approximately twenty per cent protein. The efficiency of protein utilization and . . .