Effect of Non-Protein Nitrogen Supplementation of Low Protein Rations on Laying Hen Performance with a Note on Essential Amino Acid Requirements

Abstract

YOUNG et al. (1965) and Chavez et al. (1966) have presented evidence that non-amino acid sources of nitrogen can partially replace dietary protein for the laying hen. The former results were not unexpected in view of the large proportion of the maintenance requirement (ca. 66%) which can be met by non-essential amino acids (Leveille and Fisher, 1958; Leveille et al., 1960) and the ability of this same type of nitrogen to maintain (Shapiro and Fisher, 1962) and/or partially replete limited quantities of body protein reserves (Wessels and Fisher, 1965). Also understandable was the small production advantage (3.5%, Chavez et al., 1966) obtained with non-protein nitrogen supplementation of low protein diets, because maintenance N requirement relative to that necessary for egg formation is small (ca. 27%, Shapiro and Fisher, 1965). Egg formation per se would not be expected to benefit from non-protein nitrogen as the ratio of essential: non-essential amino acids . . .