Digestion des galacto-oligosaccharides et effets nutritionnels chez le poulet de chair

Abstract : Today soyabean meal is largely used in the nutrition of monogastric animaIs. However, its digestibUity seerns not to be optimal for broiler chickens. Soya contains various molecules considered as indigestible, like galacto-oligosaccharides (GOS), which L. might be at least partly responsible for the limited value of metabolisable energy in chickens. The fact that GOS carmot be hydrolyzed by the endogenous enzymes of the host represents a loss of energy. Although the GOS can be fermented in the caeca, their contribution to the energetic balance value is unclear. ln addition it is assumed that the presence of GOS in a feed has a negative impact on its energetic value. ln the literature the effects of GOS on the nutritive value of a feed are still unclear because, even if GOS are considered as anti-nutritional factors, their presence in a feed is not correlated with a clear reduction of animal performance. A first experiment with concentration of GOS close to that of feed used in the poultry industry could not demonstrate anti-nutritional properties of these molecules. A second type of experiment based on the substitution of basal feed by GOS (replacement method) was performed to evaluate the energetic value of the GOS in vivo and deterrnine their effects on caecal fermentation, intestinal transit time and more generally on the digestibility of the feed. ln addition an in vitro experiment was carried out to study the influence on the fermentation profile in relation to the quantities of GOS added. The results of the experiments showed that there is substantial pre-caecal disappearance of GOS from the gut, although the principal site of degradation is the caeca. The contribution of GOS to the energetic value of the feed seerns to be neutral despite an acceleration of the intestinal transit and a reduction of the dry matter digestibUity which were observed when high quantities of GOS were ingested. The fermentation pathway in the caeca was influenced dose-dependently a daily intake of "medium quantities" of GOS stirnulated the production of short chain fatty acids (AGCC) while the intake of "high quantities" of GOS decreased the production of AGCC and sti.rnulated the production of lactate. The results obtained during the thesis showed that the major anti-nutritional consequence of the present of GOS in the feed is a dilution of the digestible dry matter used by the animal for its growth.
Document type :
Theses
File URL :
http://docnum.univ-lorraine.fr/prive/INPL_T_2005_JALLIER_V.pdf
Complete list of metadatas

https://hal.univ-lorraine.fr/tel-01749985
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 12:35:08 PM
Last modification on : Monday, April 16, 2018 - 10:41:28 AM

Identifiers

  • HAL Id : tel-01749985, version 1

Collections

Citation

Vincent Jallier. Digestion des galacto-oligosaccharides et effets nutritionnels chez le poulet de chair. Sciences agricoles. Institut National Polytechnique de Lorraine, 2005. Français. ⟨NNT : 2005INPL039N⟩. ⟨tel-01749985⟩

Share

Metrics

Record views

7