Relevance of functional properties of dietary fibre in diets for weanling pigs

Traditionally, feeding highly digestible ingredients and including in-feed antibiotics as growth promoters has been recommended in piglets diets. However, the ban of in-feed antibiotics as growth promoters in many countries, together with the increases in price of many ingredients, favours the study of less complex diets in the post-weaning (PW) period. In this respect, the inclusion of dietary fibre (DF) as a mean to overcome problems associated with the weaning process might be of value. In PW piglet feed, functional characteristics of fibrous ingredients are likely more important than the chemical composition of the fibrous ingredients. This article reviews the functional effects of DF on the digestive tract of piglets during the PW period. Evidence presented in this review indicates that moderate levels of insoluble fibre sources preferably as coarse particle size and when pigs have a compromised health status, might have positive effects promoting gut health during the first two weeks after weaning. These positive effects might be associated with enhanced maturation of the gastrointestinal tract (GIT) as well as with the physical effect of DF on the growth of intestinal microbiota and the blocking of the adhesion of pathogenic bacteria to the GIT mucosa. On the other hand, inclusion of soluble and rapid fermentable fibre sources in the diet for the first two weeks after weaning, especially with early weaning in farms with poor health status, might be contraindicative due to the limited digestive capacity of the piglets. Once the pigs adapt to solid feed, higher amounts of soluble and fermentable fibre sources, can be gradually included in the diet to promote healthy fermentation of undigested nutrients and better absorption of SCFA by the colon mucosa. Under poor hygiene conditions, the level of fermentable fibre and CP content of the PW diets should be limited to avoid intestinal dysbiosis, which might increase the risk of post-weaning diarrhoea (PWD).