The present research work was performed in view of investigating the effects of humidity, under the several DBT and changes of WBT, on food intake, water consumption and egg shell quality in White Leghorns based on a series of experiments. Twenty-four laying hens were kept in a temperature controlled room under 30 and 32. 5℃ at 60 and/ or 80% RH during 3 weeks in Experiment I; and under 25, 30 and 35℃ at lower humidity in Exp. II.
For confirmation, previously reported 1970 Exp. (A) and more humid 1970 Exp. (B) (unpublished, 30 and 32. 5℃, 60-70% RH) and previously reported 1971 Exp. were compared to the present data. The results obtained were as follows.
1) Each food intake per 1 kg of body weight, irrespectively of wide change of WBT and controlled by DBT, was surprisingly constant especially under higher temperature ranges.
2) Water consumption, egg weight and egg shell thickness also seemed to be controlled mainly by DBT.
3) The body weight may have a tendency to be affected by humidity in relation to evaporative system as to the thermo-regulation in chickens.