Diurnal cycles of gastric motlity in normal and fasted turkeys

Strain gage transducers were chronically implanted on the muscular stomachs of 12 young turkeys to study diurnal patterns of gastric motility. Continuous recordings were made for several days before and after a period of two or three days of fasting. Pronounced diurnal cycles in gastric motility were observed in which the frequency and amplitude of gastric contractions were increased during the daylight and depressed during darkness. Fasting caused a reduction in both frequency and amplitude and, during fasting, the diurnal cycles were somewhat obscured. Motility improved upon refeeding and cycles were agina apparent. The diurnal cycles appeared to be at least partially regulated by an intrinsic biological rhythm.