title: In vitro fermentation of total mixed diets differing in concentrate proportion: relative effects of inocula and substrates.
abstract: BACKGROUND
  In vitro techniques are used to predict ruminant feedstuff values or characterise rumen fermentation. As the results are influenced by several factors, such as the relative effects of inocula and substrates, this study aimed to examine in vitro incubation of two total mixed rations (substrates) differing in their proportion of concentrate [low (L): 350 g kg(-1) vs. high (H): 700 g kg(-1)] incubated in inocula provided by goats fed either a L or a H diet. Gas production and composition in carbon dioxide (CO2), methane (CH4 ) and hydrogen (H2), volatile fatty acids (VFAs), soluble carbohydrates (SCs) and ammonia (NH3) concentrations, and pH of the fermentation fluid were measured.
  
  
  RESULTS
  In comparison with the L inoculum and L substrate, the H ones produced more CO2 and CH4 gas, which led to higher SCs and VFA concentrations, and lower acetate-to-propionate ratio and NH3 concentration, with a predominant effect of the inoculum.
  
  
  CONCLUSIONS
  The effects of the inocula and of the substrates were additive using donor animals adapted to the diets.
authors.affiliation: INRA, UMR 791, Modélisation Systémique Appliquée aux Ruminants,16, rue Claude Bernard, F-75005 Paris, France.|AgroParisTech, UMR 791, Modélisation Systémique Appliquée aux Ruminants, 16, rue Claude Bernard, F-75005 Paris, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Serment
authors.affiliation: INRA, UMR 791, Modélisation Systémique Appliquée aux Ruminants,16, rue Claude Bernard, F-75005 Paris, France.|AgroParisTech, UMR 791, Modélisation Systémique Appliquée aux Ruminants, 16, rue Claude Bernard, F-75005 Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Giger-Reverdin
authors.affiliation: INRA, UMR 791, Modélisation Systémique Appliquée aux Ruminants,16, rue Claude Bernard, F-75005 Paris, France.|AgroParisTech, UMR 791, Modélisation Systémique Appliquée aux Ruminants, 16, rue Claude Bernard, F-75005 Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmidely
authors.affiliation: INRA, UMR 791, Modélisation Systémique Appliquée aux Ruminants,16, rue Claude Bernard, F-75005 Paris, France.|AgroParisTech, UMR 791, Modélisation Systémique Appliquée aux Ruminants, 16, rue Claude Bernard, F-75005 Paris, France.
authors.forename: Ophélie
authors.initials: O
authors.lastname: Dhumez
authors.affiliation: INRA, UMR 791, Modélisation Systémique Appliquée aux Ruminants,16, rue Claude Bernard, F-75005 Paris, France.|AgroParisTech, UMR 791, Modélisation Systémique Appliquée aux Ruminants, 16, rue Claude Bernard, F-75005 Paris, France.
authors.forename: Laurent P
authors.initials: LP
authors.lastname: Broudiscou
authors.affiliation: INRA, UMR 791, Modélisation Systémique Appliquée aux Ruminants,16, rue Claude Bernard, F-75005 Paris, France.|AgroParisTech, UMR 791, Modélisation Systémique Appliquée aux Ruminants, 16, rue Claude Bernard, F-75005 Paris, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sauvant
mesh_terms: D000085:Acetates / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D050260:Carbohydrate Metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004063:Digestion; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005285:Fermentation; D006041:Goats; D006859:Hydrogen; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008697:Methane / Q000378:metabolism; D011422:Propionates / Q000378:metabolism; D012417:Rumen
chemical_list: D000085:Acetates; D005232:Fatty Acids, Volatile; D011422:Propionates; D002245:Carbon Dioxide; D000641:Ammonia; D006859:Hydrogen; D008697:Methane
keywords: in vitro gas production; inoculum; methane production; proportion of concentrate; rumen