title: Comparison of specific methane yield of perennial ryegrass prepared by thermal drying versus non-thermal drying in small-scale batch digestion tests.
abstract: Dried milled biomass samples are frequently utilised in small-scale batch digestion tests. However, herbage chemical composition can be altered by thermal drying, and this may affect specific methane (CH4) yields. Thus, the specific CH4 yield of herbage pre- and post-ensiling, prepared by two preparation methods were compared. Perennial ryegrass samples were either non-thermally dried (i.e. subject to cryogenic conditions, -196 °C) or thermally dried (40 °C), prior to milling. Specific CH4 yield was subsequently determined in a small-scale batch digestion test. Herbage pre-ensiling yielded 204 and 243 L CH4 kg(-1)VS(added) and herbage post-ensiling yielded 212 and 188 L CH4 kg(-1)VS(added) with non-thermal dried and thermal dried sample preparation methods, respectively. Due to opposing effects of thermal drying on CH4 yields of herbage either pre- or post-ensiling, it is not recommended to use thermal drying. Instead, it is recommended that non-thermal dried herbage samples are used in small-scale batch digestion tests.
authors.affiliation: Animal & Grassland Research and Innovation Centre, Teagasc, Grange, Dunsany, Co. Meath, Ireland; School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: P
authors.initials: P
authors.lastname: Nolan
authors.affiliation: Animal & Grassland Research and Innovation Centre, Teagasc, Grange, Dunsany, Co. Meath, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: McEniry
authors.affiliation: School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: E M
authors.initials: EM
authors.lastname: Doyle
authors.affiliation: Animal & Grassland Research and Innovation Centre, Teagasc, Grange, Dunsany, Co. Meath, Ireland. Electronic address: padraig.okiely@teagasc.ie.
authors.forename: P
authors.initials: P
authors.lastname: O'Kiely
mesh_terms: D061249:Batch Cell Culture Techniques / Q000379:methods*; D003890:Desiccation; D008129:Lolium / Q000378:metabolism*; D008697:Methane / Q000096:biosynthesis*; D012820:Silage; D013696:Temperature
chemical_list: D008697:Methane
keywords: Anaerobic digestion; Grass; Methane; Silage; Thermal drying