The Use of Non-Protein Nitrogen by Laying Hens for Egg Production

Abstract

Experiments were conducted to investigate the possibility of laying hens utilizing sources of non-protein nitrogen for egg production. Sources of non-protein nitrogen were added to low protein diets composed of practical feed ingredients and to a semipurified diet composed mainly of glucose, starch, isolated soybean protein, and blood meal. Essential amino acid supplementation was used to achieve a better amino acid balance of the diets.When the nitrogen supplements were added to a diet containing 12.5% protein, and with levels of essential amino acids that approximated those recommended by the National Research Council, a graded response in egg production was obtained to two levels of supplemental urea. A similar supplementation with monosodium glutamate had no effect on egg production. A low level of diammonium citrate supplementation produced a small increase in egg production and a higher level depressed egg production and feed intake. When the level of protein in the basal diet was reduced to 11.5%, and diammonium phosphate was used as source of non-protein nitrogen there was a depression in egg production but not in feed intake or nitrogen retention.Diammonium phosphate had the same effect when supplemented to a semipurified diet that contained all essential amino acids at a level equal to or higher than that recommended by the National Research Council. When glycine was supplemented to the semipurified diet, an increase in egg production was obtained.