Abstract
Summary: A nitrogen balance experiment of ten weeks' duration with two Rhode Island Red laying hens is described.The observed variations in the retention of nitrogen for egg-producing purposes do not appear to be connected with the output of egg nitrogen or with the number of eggs laid in the various egg cycles.The view held by other workers that the nitrogen required for egg production can be largely if not entirely drawn from the food supplied during the laying period is confirmed.The marked storage of nitrogen which has been shown to occur immediately prior to the commencement of egg laying is not repeated during the laying period, and it is suggested that during a period of heavy egg production synthesis of the nitrogenous constituents of the egg proceeds at a fairly uniform rate.