Digestion dans l'intestin grêle chez le porc. 2. — Cinétique comparée de passage des digesta selon le mode de fistulation, iléocaecale ou iléo-colique post valvulaire, dans diverses conditions d'alimentation
A new technique, called post-valvular ileocolic fistulation, for collecting digesta like those normally passed towards the large intestine, is described. Nine castrated Large White pigs with a liveweight range of 47-64 kg were used to compare the post-valvular ileocolic fistulation technique with the conventional ileocecal fistulation method. Three of these pigs were fitted with electrodes for electromyography of the small intestine. Two pigs fitted with chronic electrodes were subjected alternately to long-term colic emptiness and repletion. For all the other animals, a permanent colic emptiness was chosen rather than a restitution of digesta collected because the former solution was assumed to supply a more homogenous situation for the comparison of techniques. Post-valvular ileocolic fistulation seems to be well tolerated by the animals and avoids the main causes of failures of current techniques. Electromyographic study of the small intestine motility showed the persistence of the myoelectric migrating complexes during post-valvular fistulation, provided that colic repletion is maintained by restitution of digesta. The suppression of the latter greatly changes this organization in the ileum. After a test meal, the amounts of FM [fresh matter] and DM [dry matter] collected increased from the 3rd-4th hour and reached a maximum flow rate during the 5th-6th hour; the main fraction of the dietary residual bulk passed through the ileum within 14 h. Hourly collections and determination of the amounts of digesta collected in 6 h showed that the duration of the gastrointestinal food passage was increased by 60-90 min when the functional role of the ileo-ceco-colic junction was preserved. The current techniques result in a too early derivation of digesta as compared with their true emission towards the large intestine as evidenced by post-valvular fistulation recording. In addition, the DM content of digesta collected over 24 h using the latter technique is higher (11.8%) than that of effluents derived from the ileum (10.7%). Type of starch or the level of crude protein influence digesta composition.