The Influence of Dietary Protein Level on the Response of S. C. White Leghorns to Supplementary Ascorbic Acid

THE value of ascorbic acid for maintenance of egg shell thickness under heat stress has been demonstrated by Thornton and Moreng (1958 Thornton and Moreng (1959). In those studies a simplified corn-soybean oil meal diet containing 15 percent crude protein was used. In view of the work of Patterson and Bourquin (1943), which suggested that the human ascorbic acid requirement was increased when high protein diets were consumed, it was believed necessary to study this factor in the chicken. This would seem to be particularly important since wide ranges of protein levels are currently being used in the layer rations under commercial conditions. Although the influence of ascorbic acid on protein metabolism per se is relatively unknown, the role of this vitamin in the metabolism of certain amino acids has been studied to some extent. For example, Ichihara (1954) in a review, reported the relationship of vitamin C to tyrosine and tryptophan metabolism… .