title: Processing barley grain with lactic acid and tannic acid ameliorates rumen microbial fermentation and degradation of dietary fibre in vitro.
abstract: BACKGROUND
  Cereal grains are important ingredients of ruminant diets, but their rapid degradation seriously impairs rumen fermentation and the host's health. The goal of this study was to evaluate whether processing of barley grain with 1 or 5% lactic acid (LA) and 1 or 5% tannic acid (TA), without or with an additional heat treatment (1% LAH or 1% TAH), may affect microbial ruminal abundance, fermentation profile, and nutrient degradation in vitro.
  
  
  RESULTS
  Processing with LA lowered (P < 0.05) the concentration of short-chain fatty acids (SCFAs), proportions of branched-chain SCFA, and the acetate-to-propionate ratio. Treatment with 1% TAH and 1% LAH lowered (P < 0.05) gene copy numbers of total protozoa, rumen lipopolysaccharide, and degradation of crude protein, and tended (P = 0.08) to lower the proportion of the genus Prevotella. Treatment of barley grain with 1% LA or 1% LAH stimulated Clostridium cluster XIV. Degradation of fibre was enhanced (P < 0.05) by all LA and TA treatments.
  
  
  CONCLUSIONS
  Chemical and heat treatment of barley grain modulated the ruminal fermentation profile and enhanced fibre degradation; however, processing of grain with LA seems to be superior because this effect was not associated with a concomitant depression in ruminal degradation of organic matter.
authors.affiliation: Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Deckardt
authors.affiliation: University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Barbara U
authors.initials: BU
authors.lastname: Metzler-Zebeli
authors.affiliation: Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Qendrim
authors.initials: Q
authors.lastname: Zebeli
mesh_terms: D000821:Animal Feed; D000818:Animals; D003013:Clostridium / Q000254:growth & development; D004032:Diet / Q000662:veterinary; D004043:Dietary Fiber / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism; D004063:Digestion; D002523:Edible Grain / Q000737:chemistry*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling / Q000379:methods; D000069196:Gastrointestinal Microbiome; D001467:Hordeum; D006358:Hot Temperature; D066298:In Vitro Techniques; D019344:Lactic Acid; D008070:Lipopolysaccharides; D018720:Prevotella / Q000254:growth & development; D012417:Rumen / Q000378:metabolism / Q000382:microbiology; D013634:Tannins
chemical_list: D004043:Dietary Fiber; D004044:Dietary Proteins; D005232:Fatty Acids, Volatile; D008070:Lipopolysaccharides; D013634:Tannins; D019344:Lactic Acid
keywords: grain cereal processing; lipopolysaccharide; rumen ecology; rumen health; short-chain fatty acids