Some responses of laying hens to induced arrest of egg production

Arrest of egg production was induced by forced-molt (artificial light deprivation and feed deprivation for 10 days followed by 20 days of grain only) and by low-calcium regime in one experiment, and by Nicarbazin in another. Post-arrest production and shell quality significantly surpassed the control in the force-molt but not in the low-Ca treatment. At the onset of production, following the pause, egg weight and shell weight per unit of surface area rapidly increased up to the 9-10th egg. In the second trial, feed intake declined in about one week after the arrest in egg production to a non-layer level. During this week, body weight increased. However, despite the increase in feed intake after the onset of production, pre-arrest levels were not obtained even after 11 days, resulting in a loss of body weight. The separation of flock production into its components, rate of production of the layers, and the proportion of layers in the flock, is proposed.