Degradation and physicochemical changes of barley and pea fibre along the gastrointestinal tract of pigs

Abstract

The degradation of barley and pea ®bres along the gastrointestinal tract (GIT) of pigs and its relation to changes in some of their physicochemical properties were investigated. Ileal and caecal digesta containing pea cotyledon ®bre showed the highest (P < 0.05) swelling (33.1±36.7 ml g À1 DM) and water retention capacity measured by centrifugation (17.9±21.2 g g À1 DM) and by osmotic pressure (9.0±9.1 g g À1 DM). The particle size of barley hull did not change along the GIT (160±207 mm), whereas that of pea cotyledon and pea hull was drastically reduced in faeces (62±65 mm) compared with the ileum and caecum (198±415 mm). The digestibility of non-starch polysaccharides (NSP) was lowest for barley hull in the ileum (5% of intake), caecum (0% of intake) and faeces (26% of intake). The digestibility of NSP was highest for pea cotyledon ®bre and dehulled barley in the proximal hindgut and for pea cotyledon ®bre in faeces (96% of intake for pea cotyledon vs 74±82% of intake for dehulled barley and pea hull). In conclusion, hydration properties and particle size add valuable information when describing the fermentation of ®bres in the GIT. However, they cannot be used alone as indicators of the extent of fermentation of different ®bres. The results also suggested that the ®bre source and the organisation and ligni®cation of the cell walls lead to different fermentation processes along the GIT of pigs. # 2001 Society of Chemical IndustryKeywords: ®bre; pigs; physicochemical properties; fermentation process INTRODUCTION Pig diets contain approx 60±70% carbohydrates, of which 14±22% is ®bre (non-starch polysaccharides lignin). Studies of the physiological and nutritional implications of ®bre on the animal, and the factors affecting them, seem therefore of great relevance.As stated by Robertson, 1 dietary ®bre (DF) consists of a complex group of substances that form a matrix, which determines the rate and extent of nutrients released during gastrointestinal transit. Thus chemical composition, structure, physical and physicochemical properties as a whole, and not individually, will determine the digestion and physiological effects of different ®bre sources along the gastrointestinal tract of the animal.2±4 Amongst the properties of ®bre believed to in¯uence its physiological and nutritional effects are solubility, viscosity, hydration properties, particle size, fermentability and binding of organic compounds.

Effect of coarse ground corn, sugar beet pulp and wheat bran on the voluntary intake and physicochemical characteristics of digesta of growing pigs

“…However, results obtained in the distal colon were contradictory, because animals fed SBP had a higher WRC and a lower concentration of NSP compared to WB fed animals (293.2, and 313.8 g/ kg DM digesta, respectively, data not shown). Canibe and Bach Knudsen (2001) found no differences in the faecal WRC of pigs fed pea cotyledon (96% digestibility) or pea hull (82% digestibility), even when NSP amount was higher in the faeces of pigs fed pea hull. Thus, it could be suggested that water retention capacity is correlated to the amount of dietary fibre, but also dependent on the composition and structural features of fibre (Bertin et al, 1988).…”

“…The content of dietary fibre and the feed particle size influence to some extent the digestive processes in the gastrointestinal tract (GIT, Cummings and Englyst, 1995), the physicochemical characteristics of digesta (Canibe and Bach Knudsen, 2001;Mikkelsen et al, 2004), gut morphology (Jorgensen et al, 1996), and mucosal maturation and integrity (Goodlad et al, 1995;Stark et al, 1995;Brunsgaard, 1998). The effects of dietary fibre and feed form on the gastrointestinal tract physiology can be direct or indirect.…”

Potential Rates of Fermentation in Digesta from the Gastrointestinal Tract of Pigs: Effect of Feeding Fermented Liquid Feed

“…The chemical composition of dry feed and FLF was analyzed by standard methods for determining the content of energy, ash, fat, crude protein, starch, and specific saccharides (2).…”

Protein Sources in Ruminant Nutrition

“…The carbohydrate fraction includes the low molecular-weight sugars, starch and various non-starch-polysaccharides (NSP) (Bach Knudsen, 1997). The NSP and lignin are the principal components of cell walls and are commonly referred to as dietary fibre (Theander et al, 1989;Canibe and Bach Knudsen, 2002). Generally, faba beans and peas are rich in starch (422-451 and 478-534 g/kg dry matter, respectively) (DLG, 1999;Jezierny, 2009), whereas lupins have comparatively low levels of starch (42-101 g/kg dry matter) (DLG, 1999;Jezierny, 2010).…”