title: Effects of Aspergillus spp. exogenous fibrolytic enzymes on in vitro fermentation of tropical forages.
abstract: BACKGROUND
  Cellulose and hemicellulose are quantitatively the most important structural carbohydrates present in ruminant diets. Rumen micro-organisms produce enzymes that catalyse their hydrolysis, but the complex network formed by structural carbohydrates and lignin reduces their digestibility and restricts efficient utilisation of feeds by ruminants. This study aimed to produce two enzymatic extracts, apply them in ruminant diets to determine the best levels for ruminal digestibility and evaluate their effects on in vitro digestibility.
  
  
  RESULTS
  In experiment 1 a two-stage in vitro technique was used to examine the effects of different enzymatic levels of Aspergillus japonicus and Aspergillus terricola on tropical forages. Enzyme addition had minor effects on corn silage at the highest enzymatic level. In experiment 2 an in vitro gas production (GP) technique was applied to determine apparent in vitro organic matter digestibility and metabolisable energy. The addition of enzymes in GP showed interesting results. Good data were obtained using sugar cane and Tifton-85 hay supplemented with extracts of A. japonicus and A. terricola respectively.
  
  
  CONCLUSIONS
  Overall, the study suggests that addition of crude extracts containing exogenous fibrolytic enzymes to ruminant diets enhances the effective utilisation of ruminant feedstuffs such as forages.
authors.affiliation: Biochemical Department, Sao Paulo University (USP), Ribeirão Preto, SP, Brazil.
authors.forename: Fernanda D A
authors.initials: FD
authors.lastname: Facchini
authors.forename: Victor R A
authors.initials: VR
authors.lastname: Reis
authors.forename: Anna Paula
authors.initials: AP
authors.lastname: Roth
authors.forename: Karla A
authors.initials: KA
authors.lastname: Magalhães
authors.forename: Simone C
authors.initials: SC
authors.lastname: Peixoto-Nogueira
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Casagrande
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Reis
authors.forename: Maria de Lourdes T M
authors.initials: Mde L
authors.lastname: Polizeli
mesh_terms: D000821:Animal Feed; D000818:Animals; D001230:Aspergillus / Q000201:enzymology*; D001688:Biological Products / Q000494:pharmacology*; D002482:Cellulose / Q000378:metabolism; D004032:Diet; D004043:Dietary Fiber / Q000378:metabolism*; D004063:Digestion / Q000187:drug effects*; D005285:Fermentation; D005740:Gases / Q000378:metabolism; D006109:Poaceae; D011134:Polysaccharides / Q000378:metabolism; D012417:Rumen / Q000187:drug effects* / Q000382:microbiology / Q000502:physiology; D012820:Silage
chemical_list: D001688:Biological Products; D004043:Dietary Fiber; D005740:Gases; D011134:Polysaccharides; C007916:hemicellulose; D002482:Cellulose