LE pH DANS LE TUBE DIGESTIF DES OISEAUX

Abstract

Un des aspects les plus importants de la digestion est certes la transformation enzymatique des constituants nutritifs complexes en produits simples susceptibles d'être absorbés. Mais l'activité enzymatique étant entre autres conditionnée par la concentration en ions hydrogènes, il apparaît clairement que le pH des différents secteurs du tube digestif a un rôle déterminant dans l'efficacité de la digestion.

The effect of the microflora on gastrointestinal pH in the chick

“…In the experiment reported here pH readings for the conventional crop contents were lower than the 5-5 and 5-8 reported by Herpol and van Grembergen (1961) and Ivorec-Szylit (1971) respectively. This may have been as a result of regurgitation of acid from the proventriculus into the crop during manipulation before the artery clamp was applied, something which other workers were able to avoid, or differences either in the pH of the food or feeding regimes used.…”

“…A comparison was made, however, between small numbers of starved and fully fed conventional birds because of reports that the numbers of bacteria in the gut of some animals were affected by the food in the gut (Morishita and Ogata, 1970). Farner (1943) noted that the gizzard contents became less acid after death which was ascribed by Herpol and van Grembergen (1961) to interdiffusion between contents of the gizzard and adjacent parts of the gut. In the experiments reported here live, anaesthetised birds were used and, to minimise, any mixing between adjacent portions, manipulation of the gut was avoided as much as possible.…”

Non‐specific Antimicrobial Defences of the Avian Egg, Embryo and Neonate

“…typhimurium (Cox, Davis, Watts & Colmer, 1972). The p H of the proventriculus and gizzard, which can be as low as 1-5 (Herpol &van Grembergen, 1961), would seem to present a formidable obstacle to any organism attempting to colonize the lower gut.…”