Physiology of feed efficiency in the pig: emphasis on the gastrointestinal tract and specific dietary examples

Abstract

A sound and robust structure of the gastrointestinal tract (GIT) with appropriate physiological functions is critical during the various life phases of pig growth, to ensure optimum health of the GIT that in turn ensures optimum pig production. This is especially the case in the period immediately following weaning, when there are a number of abrupt simultaneous insults imposed on young pigs that cause temporal changes to the structure and function of the GIT. These alterations contribute to the well-described post-weaning ‘growth check’, and although it is reasonably well understood what causes these changes, continuation of the ‘growth check’ in commercial pig production around the world continues largely unabated. Given the close connection between the physiology of the GIT and pig performance and health, this chapter focuses on a number of influences, before and after weaning, that influence the structure and function of the GIT that in turn impact feed efficiency. This chapter, as with others described in this book, demonstrates that the physiology of the GIT, and indeed the entire pig, is the cornerstone for improved feed efficiency