The Influence of Feed Efficiency on the Phosphorus Requirement for Growth and Bone Calcification in the Chick

EVER since the development and widespread use of high energy broiler and starter rations, the adequacy of many specific nutrients in those rations has been open to some questioning. On the basis of the greater gain per unit of feed consumed on the high energy rations over the standard type ration in use in 1944-45, a three pound bird consumes approximately three fourths the nutrients consumed by a three pound bird on older type rations. Singsen (1951) believed that today’s birds are growing on the margin of safety provided in earlier nutrient recommendations. One of the nutrient recommendations of the National Research Council believed by Singsen (1951) to be critical is for the mineral phosphorus which has been the subject of the present investigation. Two exploratory experiments were conducted to find a low P ration that would support maximum growth and that could be changed in its energy content without …