An experiment was made in which laying hen diets containing four different levels of dicalcium were each fed to two replicate groups of 10 strains of S.C.W.L. hens. The apparent metabolizable energy (A.M.E.) values of the diets were measured. There was a small but significant (P less than 0.01) linear increase in the dietary A.M.E. value associated with decreasing levels of phosphorus. The A.M.E. values did not differ between strains of birds (P greater than 0.05) and there was no phosphorus level x strain interaction (P greater than 0.05).
