Nutrient Requirements of Growing Chicks

Abstract

The nutritional disorder of which leg weakness is the most outstanding symptom is familiar to all poultry nutrition investigators. We now recognize in the common “leg weakness” a disorder fundamentally similar to rickets in other animals as shown by changes in the blood and bone composition of affected birds. Rickets is a bone disease due to faulty calcium and phosphorus assimilation, the absorption of these very essential elements being influenced by the calcium and phosphorus content of the ration, by the vitamin content of the ration, or by the action of certain rays in the spectrum, these rays being designated as the ultraviolet.Using the rat as the experimental animal, McCollum, Simmonds, Shipley and Park1 have shown the ratio between calcium and phosphorus in the diet is of greater significance in the prevention of rickets than are the absolute amounts of these elements. It is not to be hoped that .