title: Effects of disodium fumarate on in vitro rumen microbial growth, methane production and fermentation of diets differing in their forage:concentrate ratio.
abstract: The effects of disodium fumarate on microbial growth, CH4 production and fermentation of three diets differing in their forage content (800, 500 and 200 g/kg DM) by rumen micro-organisms in vitro were studied using batch cultures. Rumen contents were collected from four Merino sheep. Disodium fumarate was added to the incubation bottles to achieve final concentrations of 0, 4 and 8 mm-fumarate, and (15)N was used as a microbial marker. Gas production was measured at regular intervals from 0 to 120 h of incubation. Fumarate did not affect (P>0.05) any of the measured gas production parameters. In 17 h incubations, the final pH and the production of acetate and propionate were increased linearly (P<0.001) by the addition of fumarate. Fumarate tended to increase (P=0.076) the organic matter disappearance of the diets and to decrease (P=0.079) the amount of NH3-N in the cultures. Adding fumarate to batch cultures tended (P=0.099) to decrease CH4 production, the mean values of the decrease being 5.4 %, 2.9 % and 3.8 % for the high-, medium- and low-forage diet, respectively. Fumarate tended to increase (P=0.082) rumen microbial growth for the high-forage diet, but no differences (P>0.05) were observed for the other two diets. These results indicate that the effects of fumarate on rumen fermentation depend on the nature of the incubated substrate, the high-forage diet showing the greatest response.
authors.affiliation: Departamento de Producción Animal I, Universidad de León, 24071 León, Spain.
authors.forename: R
authors.initials: R
authors.lastname: García-Martínez
authors.forename: M J
authors.initials: MJ
authors.lastname: Ranilla
authors.forename: M L
authors.initials: ML
authors.lastname: Tejido
authors.forename: M D
authors.initials: MD
authors.lastname: Carro
mesh_terms: D000085:Acetates / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology; D005285:Fermentation; D005650:Fumarates / Q000008:administration & dosage*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007773:Lactates / Q000378:metabolism; D008697:Methane / Q000378:metabolism*; D011422:Propionates / Q000378:metabolism; D012417:Rumen / Q000382:microbiology*; D012756:Sheep / Q000378:metabolism / Q000502:physiology*
chemical_list: D000085:Acetates; D005650:Fumarates; D007773:Lactates; D011422:Propionates; D000641:Ammonia; C032005:fumaric acid; D008697:Methane