Intestinal Degradation of Dietary Carbohydrates - from Birth to Maturity

摘要

Dietary carbohydrates constitute a major fraction of the diet for pigs and consist of mono-, di- and oligosaccharides and two broad classes of polysaccharides - starch and non-starch polysaccharides (NSP). The activity of the various carbohydrate-degrading enzymes adapts to the age of the animal and to changes in dietary composition. This ensures in most cases an efficient pre-caecal digestion of lactose in the suckling period and of sucrose and starch after weaning. The diverse population of anaerobic bacteria in the large intestine ferments carbohydrates (mostly NSP) that are not degraded in the small intestine. Factors that influence the breakdown of NSP in the large intestine include the source of NSP, solubility, degree of lignification, levelof inclusion in the diet, transit time, age and weight of the animal and microbial composition. The large intestine grows progressively larger than the small intestine in older animals, which enables sows to have a higher capacity than growing pigs to degrade NSP components.