J. Anim Sci., doi: 10.2527/jas.2006-431
©Copyright, 2006, The American Society of Animal Science
Sites of nutrient digestion in growing pigs: Effect of dietary fiber
A. Wilfart 1,
L. Montagne 2,
P. H. Simmins 3,
J. van Milgen 1,
J. Noblet 1*
1 INRA, UMR Systèmes d'Elevage, Nutrition Animale et Humaine, INRA-Agrocampus Rennes, F-35590 Saint-Gilles, France
2 Agrocampus Rennes, UMR Systèmes d'Elevage, Nutrition Animale et Humaine, INRA-Agrocampus Rennes, F-35590 Saint-Gilles, France
3 Danisco Animal Nutrition, Marlborough Wiltshire, SN8 IXN, United Kingdom
* To whom correspondence should be addressed. E-mail: Jean.Noblet{at}rennes.inra.fr.
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Abstract |
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The impact of dietary fiber on fecal digestion is well-known and provides a comprehensive approach towards nutrient digestibility and availability. Little quantitative information is available on digestion of fiber in the different segments of the gastro-intestinal tract (GIT). The objectives of this study were to obtain a method allowing the quantification of the digestive process in different segments of the GIT, and to study the impact of dietary fiber on nutrient digestibility. Six barrows (average initial BW of 30 kg and fitted with a simple T-cannula at the proximal duodenum and distal ileum) were used in a replicated 3 x 3 Latin square design. In each period, pigs were offered 1 of 3 diets differing in the fiber content (low, medium, and high). Differences in the fiber content were created by replacing wheat and barley with wheat bran. Titanium dioxide was included in the diet as an indigestible marker to determine the apparent digestibility coefficients in different segments of the GIT. The apparent digestibility of ash, CP, DM, and OM increased in the different segments of the GIT. Duodenal digestibility coefficients were negative for ash (e.g., -39.9% for the medium- and high-fiber diet), indicating important endogenous mineral secretions in the stomach and by digestive glands. The duodenal digestibility of other nutrients and OM were positive but close to zero and numerically lower in the diets with the higher fiber content. The fiber content in the diet did not affect the apparent ileal digestibility of nutrients. Increasing the fiber content in the diet affected the fecal digestibility of CP, ether extract, and energy (P < 0.01). The method used for studying sites of digestion in the digestive tract provides promising results but it is limited due to the high variability that is likely caused by sampling limitations and variation between animals.
Key Words:
dietary fiber, digestion, endogenous secretions, pig
