title: Effects of California chaparral plants on in vitro ruminal fermentation of forage and concentrate diet.
abstract: BACKGROUND
  The combustible nature of chaparral plants has been attributed to the presence of secondary compounds such as phenolic acids, flavonoids and essential oils, among others. However, the implication of the antimicrobial properties of secondary compounds of chaparral in modulating rumen microbial metabolism has not been determined. The effects of 11 chaparral plants on rumen microbial fermentation were assessed in an in vitro batch culture fermentation fed a barley silage:barley grain-based low concentrate (LC) and high concentrate (HC) diets.
  
  
  RESULTS
  With LC, gas production [g dry matter (DM) incubated] and DM disappearance (DMD) were unaffected by Adenostoma fasciculatum, Ceanothus cuneatus, Baccharis pilularis or Eriodictyon californicum, but all plants except C. cuneatus decreased (P < 0.05) CH(4) production. With HC diet, all species except A. fasciculatum decreased (P < 0.01) total gas produced. Total volatile fatty acids (VFA) produced, molar proportions of acetate, propionate and butyrate, and the acetate:propionate (A:P) ratio were unaffected by chaparral addition to both HC and LC diets. Increased concentrations of A. fasciculatum and E. californicum decreased (linear; P < 0.05) fermentability and productions of CH(4) and NH(3) -N.
  
  
  CONCLUSIONS
  Among all chaparral species investigated A. fasciculatum and E. californicum added as 10% of LC diet showed some potential to exert beneficial effects on rumen microbial fermentation.
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada. nenarvaez@gmail.com
authors.forename: Nelmy
authors.initials: N
authors.lastname: Narvaez
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Xu
authors.forename: Tim
authors.initials: T
authors.lastname: McAllister
mesh_terms: D000821:Animal Feed; D000818:Animals; D031175:Baccharis; D002140:California; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D005232:Fatty Acids, Volatile / Q000096:biosynthesis; D005285:Fermentation; D005503:Food Additives; D001467:Hordeum; D066298:In Vitro Techniques; D008697:Methane / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D010945:Plants, Edible / Q000737:chemistry*; D027823:Rhamnaceae; D027824:Rosaceae; D012417:Rumen / Q000378:metabolism / Q000382:microbiology*; D012820:Silage
chemical_list: D005232:Fatty Acids, Volatile; D005503:Food Additives; D008697:Methane