The Relationship Between Feed Intake and Frequency of the Migrating Motor Complex in Domestic Turkeys: Is There a Cephalic Phase?

ABSTRACT Two studies were performed in order to test for the presence of a cephalic inhibition of migrating motor complexes (MMC) in domestic turkeys. Birds were implanted with two or three strain gauge transducers on the ileum and subjected to one of two different protocols. In Study 1 recordings of ileal motility were made under three feeding conditions: fed, fasted, and with feed pans in place before the birds but covered with plexiglass. In Study 2 the birds were either fasted, fasted with feed pans returned as soon as an MMC registered in the most orad gauge, or fasted with a minor disruption in the room (to simulate feed pan return) as soon as an MMC registered in the most orad gauge. Data from trials involving plexiglass plates did not differ significantly from data from fasted birds, and both differed significantly from the data from fed birds. Likewise, no significant differences were seen among any of the three feeding categories of Study 2. The present data show that neither the anticipation of eating, nor the presence of feed in the mouth and esophagus seem to directly influence the initiation or propagation of ileal MMC contractile activity in turkeys, supporting the view that extrinsic neural pathways are not responsible for the inhibition of the MMC. (Key words: turkey, migrating motor complex, feed intake, ileum, cephalic inhibition