Exploring the in vivo digestion of plant proteins in broiler chickens.
The use of various protein sources (industry by-products, proteaginous) in poultry diets requires a greater understanding of protein digestion mechanisms. The aim of this study was to characterize the molecular actors required for protein digestion in broilers fed 4 different diets containing soybean meal, rapeseed meal, pea, or corn distiller's dried grain with solubles as the only protein source. The digesta of the digestive tract segments were collected and soluble proteins were analyzed by SDS-PAGE. SDS-PAGE analyses revealed 5 ubiquitous bands in digesta of all digestive tract segments regardless of the diet, whereas 3 bands were diet-specific. The digesta of the jejunum were further submitted to proteomic analysis. Forty-two proteins of chicken origin and 17 plant proteins were identified in digesta samples by mass spectrometry. Fifteen proteins of chicken origin were specific to one diet and 18 were common to all diets. By homology with mammals, these proteins are thought to be involved in protein, lipid, carbohydrate, and nucleic acid metabolism and also in intestinal homeostasis. Some of the 17 plant proteins were found to be not fully digested (soybean meal, rapeseed meal, and pea diets) and others were identified as protease inhibitors (soybean meal and pea diets). This study provides a comprehensive analysis of the physiological proteins involved in the digestion of 4 protein sources used in broiler diets. Such an approach, combined with the analysis of insoluble components of these different protein sources, would contribute to define whether these protein sources could be more largely used in poultry nutrition. It also would allow identifying ways to improve their digestibility in broiler chickens (feed additives such as exogenous proteases or processing to inactivate anti-nutritional factors, for instance).
INRA, UR83 Poultry Research Unit, 37380 Nouzilly, France.
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Recoules
INRA, UR83 Poultry Research Unit, 37380 Nouzilly, France.
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Sabboh-Jourdan
INRA, UR83 Poultry Research Unit, 37380 Nouzilly, France.
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Narcy
INRA, UR83 Poultry Research Unit, 37380 Nouzilly, France.
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Lessire
INRA, Plat-form for Integrative Analysis of Biomolecules and Phenomic of Animals of Bio-agronomic Interest, 37380 Nouzilly, France.|INRA, UMR INRA 85, Physiology of Reproduction and Behaviors, 37380 Nouzilly, France.|CNRS, UMR 7247, 37380 Nouzilly, France.|University of François Rabelais, 37000 Tours, France.
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Harichaux
INRA, Plat-form for Integrative Analysis of Biomolecules and Phenomic of Animals of Bio-agronomic Interest, 37380 Nouzilly, France.|INRA, UMR INRA 85, Physiology of Reproduction and Behaviors, 37380 Nouzilly, France.|CNRS, UMR 7247, 37380 Nouzilly, France.|University of François Rabelais, 37000 Tours, France.
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Labas
INRA, UR83 Poultry Research Unit, 37380 Nouzilly, France.
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MJ
Duclos
INRA, UR83 Poultry Research Unit, 37380 Nouzilly, France.
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Réhault-Godbert
D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D029741:Brassica rapa / Q000737:chemistry; D002645:Chickens / Q000378:metabolism / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000378:metabolism*; D004063:Digestion / Q000502:physiology*; D005766:Gastrointestinal Contents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D018532:Pisum sativum / Q000737:chemistry; D010940:Plant Proteins / Q000378:metabolism*; D013025:Glycine max / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
D004044:Dietary Proteins; D010940:Plant Proteins
chicken; digestion; protein; proteomic