Proteolysis During Ensilage of Forages Varying in Soluble Sugar Content

Awduron Sefydliadau
  • D. R. Davies(Awdur)
    Institute of Grassland and Environmental Research
  • R. J. Merry(Awdur)
    Institute of Grassland and Environmental Research
  • A. P. Williams(Awdur)
    Institute of Grassland and Environmental Research
  • Eleanor Lydia Bakewell(Awdur)
  • Dave Leemans(Awdur)
  • John Tweed(Awdur)
Math Erthygl
Iaith wreiddiolSaesneg
Tudalennau (o-i)444-453
CyfnodolynJournal of Dairy Science
Rhif y cyfnodolyn2
Dangosyddion eitem ddigidol (DOIs)
StatwsCyhoeddwyd - Chwef 1998
Cysylltiad parhaol
Gweld graff cysylltiadau
Fformatau enwi


The effect of contrasting concentrations of water-soluble carbohydrates of herbage on silage fermentation and composition was examined using grass with high [250 g/kg of dry matter (DM)] concentrations of water-soluble carbohydrates and grass and clover with low (66 g/kg of DM) concentrations of water-soluble carbohydrates. Herbages were ensiled untreated, after inoculation with lactic acid bacteria, or after treatment with formic acid. Good quality silages were produced from herbage with high concentrations of water-soluble carbohydrates, regardless of treatment, and all pH values were below 3.7 after 90 d of ensilage. However, the silage formed from inoculated herbage had a significantly lower concentration of ammonia N and a significantly higher proportion of residual ribulose-1,5-bisphosphate carboxylase compared with the other two silages. Fast protein liquid chromatography® (Pharmacia, Uppsala, Sweden) was used to measure ribulose-1,5-bisphosphate carboxylase, and measurement of true plant protein fractions in herbage and silage showed benefits over traditional measurements such as the measurement of N and ammonia N. Herbages with low concentrations of water-soluble carbohydrates produced inferior quality silages that had lower ribulose-1,5- bisphosphate carboxylase contents and higher ammonia N contents, regardless of treatment; few significant differences were observed among treatments. Under good ensiling conditions, when available water-soluble carbohydrate is adequate, the use of inoculants can improve fermentation characteristics and increase the ribulose-1,5-bisphosphate carboxylase content of silages. However, when the herbage has low concentrations of water-soluble carbohydrates, even in inoculated herbages, lactic acid bacteria may follow a heterofermentative pathway instead of a homofermentative pathway, which can result in a decrease in silage quality and a reduction in intact ribulose-1,5-bisphosphate carboxylase.