Magnesium Requirement of the Young Chick Determined with a “Magnesium-Free” Diet

ALMQUIST (1942) concluded that the chick requires 400 p.p.m. of dietary magnesium for optimum growth and survival. Using purified diets, Snyder (1954) and Scott et al. (1956) could not improve chick growth with supplemental levels of magnesium greater than 250 and 100 p.p.m., respectively. Moeller (1959) found the magnesium requirement of the chick to be similar to that suggested by the National Research Council (1954) of 220 mg./lb. of diet. In all studies cited, the basal diets employed contained appreciable amounts of magnesium of unknown availability. Recently, Gardiner et al. (1959) were able to reduce the magnesium content of their glucose-isolated soybean protein basal diet to 75 p.p.m. by using only reagent grade chemicals in the salt mixture. They report that the chicks’ requirement for magnesium, as measured by growth and clinical deficiency symptoms, was of the order of 250 p.p.m. In the present study, a basal diet, essentially free…