Food, calcium and water intakes by hens lit continuously from hatching

Five individually caged Leghorn hens, reared from hatching under continuous light and having their ovipositions uniformly scattered throughout the 24‐h period, were used to study voluntary intakes of a diet low in calcium, oyster shell and water. 2. Food intake was high just after ovulation, decreased during the first 16 h of egg formation, rose transiently 20 to 22 h after ovulation and was minimal just before oviposition. 3. Oyster shell intake was characterised by three peaks, two coincided with those of food diet but the third, occurring between 8 and 12 h after previous oviposition, could be related to the immediate calcium need of shell formation. 4. Water intake followed a similar pattern to food intake but there was an independent rise during albumen plumping (6 to 8 h after previous oviposition).