Phase relationship of the circadian rhythms of feed intake, caecal motility and production of soft and hard faeces in domestic rabbits.

In rabbits kept under 12:12 h light conditions, caecal contractions were recorded by implanted strain gauges or induction coils. In animals fed ad libitum caecal contraction frequency varied cyclically in phase with the circadian rhythm of feed intake. Both had their minimum during the time of soft faeces production. Thus all 3 functions seem to depend on the same circadian clock. The close link between caecotrophy and caecal contractions can, however, be upset by either time-restricted feeding or by fasting.