Non-Protein Nitrogen Studies in Laying Hens

Abstract

Four experiments were conducted with laying hens to examine the effectiveness of non-protein nitrogen supplementation. Significant increases in egg production were obtained with three experiments employing diammonium citrate, ammonium sulfate, and diammonium phosphate as non-protein nitrogen sources. Non-essential nitrogen consumptions of hens fed diets which responded to non-protein nitrogen supplementation were below 1.4 gm./day. The non-protein nitrogen additions increased the non-essential nitrogen intakes to 1.4-1.9 gm./day. The results of these experiments suggest that the conversion of essential amino nitrogen to non-essential nitrogen by hens fed the diets in these studies was relatively inefficient and that the non-protein nitrogen additions exerted a "sparing" effect on essential amino nitrogen.These data suggest that the minimum amount of essential amino nitrogen required for egg production levels of 70-75% was in the order of 1.1 gm./day with the amino acid balances employed. The non-essential nitrogen requirement appears to be 1.4-1.9 gm./day, of which 0.4 gm. could be furnished by non-protein nitrogen sources.

The effect of sodium sulphate and methionine on the utilisation of non‐protein nitrogen by laying hens

“…The values obtained are similar to those obtained by Reid et al (1972) who used ammonium sulphate as the NPN supplement. They are also in accord with those of Fernandez et al (1973) who found that the nitrogen supplied by DAP is not utilised for egg production.…”

“…These data are in accord with those of Reid et al (1972) and indicate that between 1-3 and 1*4 g of non-essential amino acid nitrogen (NEN) are needed at this level of EN consumption. On the other hand, as shown in Table 2, it is not possible to establish a relationship between EN and NEN.…”

“…The addition of DAC, equivalent to 25 g protein/kg (N x 6-25), to the diet containing 135-6 g protein/kg did not improve egg production. This contrasts with the results obtained by Reid et al (1972) who found significant increases in egg production when DAC was added to diets containing 120 or 160 g protein/kg. Nevertheless, their diet containing 160 g protein/kg contained 5% less sulphur amino acids than the basal diet (162-5 g protein/kg) of the present study.…”

“…Several workers (e.g. Womack et al, 1953;Moran et al, 1967;Akintunde et al, 1968;Bornstein and Lipstein, 1968) found no evidence that laying hens were able to utilise NPN sources for egg production, while others (Reid et al, 1972;Fernandez et al, 1973) did. At the same time Damron and Harms (1973) found that laying hens could utilise inorganic sulphate to replace part of the sulphur amino acid requirements, though an earlier study (Jansen, 1972) had failed to demonstrate such a relationship.…”

L‐aspartic acid and urea supplementation of low‐protein layer diets1

“…Reid et al (1972) demonstrated that addition of diammonium citrate (DAC) or phosphate (DAP) to a low-protein diet based on soyabean and milo improved egg production. DAP supplementation of a similar fishmeal-based diet did not improve performance.…”