A scheme for the separation and estimation of nitrogenous components of the excreta from poultry

An account is given of the development of a new scheme for assessing the relative proportions of nitrogenous end‐products of digestion and metabolism in excreta from laying hens. A series of solvent extractions with methanol‐chloroform‐water, phenol‐acetic acid‐water and lithium carbonate solution removed over 90 per cent of the nitrogen from excreta. In each extract estimations were made of the concentrations of certain nitrogenous components considered to be important such as urate, ammonia, urea, creatine, creatinine and amino acids.

Fractionation of nitrogen in a sample of excreta showed that over half the nitrogen appeared in the methanol‐water extract and about a third in the phenol‐acetic acid‐water extract. About 60 per cent of the extractable nitrogen was derived from urate, about 10 per cent from large non‐dialysable molecules, 9 per cent from ammonia, 2 per cent from free amino acids, possibly 3 per cent from peptides, 2 per cent from urea and 1 per cent from creatine and creatinine.