Development of gastrointestinal and pancreatic functions in mammalians (mainly bovine and porcine species): influence of age and ingested food

This review summarizes recent advances in knowledge on the development of digestive tissues and their productions as well as mechanisms of regulation in response to age and ingested food in mammalian species (mainly bovine and porcine species).In the first two sections, changes are reported for stomach, pancreas and small intestine, and examined in relation to different situations (colostral, milk feeding and weaned periods).The implication of some regulatory substances (growth factors, gut regulatory peptides and neurohormonal substances) in regulation mechanisms is dis- cussed over these periods.For example, the plasma pattern of several gut regulatory peptides and the expression of their specific receptors could explain certain phenomena of digestive development.Recent cellular and molecular aspects of regulation of the digestive enzyme production are also reported.Finally, an approach to interactions existing between age and ingested food is given in the last section.In conclusion, although some phenomena are well established, it is often difficult to distinguish what the age-and food-dependent events are in the development of the digestive function.© Inra/Elsevier, Paris age / food / gastrointestinal tract / pancreas / digestive enzyme / gut regulatory peptide / growth factor / dietary bioactive substance Résumé ― Développement des fonctions gastrointestinales et pancréatiques chez les mammi- fères (principalement chez les bovins et les porcins) : effets de l'âge et de l'aliment.Cet article de synthèse résume les nouvelles connaissances concernant l'influence de l'âge et de l'aliment sur le développement des tissus digestifs et de leurs productions ainsi que sur leurs régulations chez les mam- mifères (principalement chez les bovins et les porcins).Dans les deux premières parties, les modifi- cations observées au niveau de l'estomac, du pancréas et de l'intestin grêle sont examinées dans différentes situations (périodes colostrale et d'allaitement, et après le sevrage).Pendant ces périodes, l'implication de substances régulatrices (telles que des facteurs de croissance, des peptides régulateurs digestifs, des substances neurohormonales) est décrite.Par exemple, les profils plasmatiques de plu-