title: Nutrient and energy content, in vitro ruminal fermentation characteristics and methanogenic potential of alpine forage plant species during early summer.
abstract: BACKGROUND
  Plants growing on alpine meadows are reported to be rich in phenols. Such compounds may affect ruminal fermentation and reduce the plants' methanogenic potential, making alpine grazing advantageous in this respect. The objective of this study was to quantify nutrients and phenols in Alpine forage grasses, herbs and trees collected over 2 years and, in a 24 h in vitro incubation, their effects on ruminal fermentation parameters.
  
  
  RESULTS
  The highest in vitro gas production, resulting in metabolisable energy values around 10 MJ kg⁻¹, were found with Alchemilla xanthochlora and Crepis aurea (herbaceous species) and with Sambucus nigra leaves and flowers (tree species). Related to the amount of total gas production, methane formation was highest with Nardus stricta, and lowest with S. nigra and A. xanthochlora. In addition, Castanea sativa leaves led to an exceptional low methane production, but this was accompanied by severely impaired ruminal fermentation. When the data were analysed by principal component analysis, phenol concentrations were negatively related with methane proportion in total gas.
  
  
  CONCLUSIONS
  Variation in methane production potential across the investigated forages was small. The two goals of limited methane production potential and high nutritive value for ruminants were met best by A. xanthochlora and S. nigra.
authors.affiliation: ETH Zurich, Institute of Agricultural Sciences, Universitaetstrasse 2, 8092 Zurich, Switzerland.
authors.forename: Anuraga
authors.initials: A
authors.lastname: Jayanegara
authors.forename: Svenja
authors.initials: S
authors.lastname: Marquardt
authors.forename: Michael
authors.initials: M
authors.lastname: Kreuzer
authors.forename: Florian
authors.initials: F
authors.lastname: Leiber
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004063:Digestion; D017753:Ecosystem; D007887:Fabaceae / Q000737:chemistry; D005285:Fermentation; D019684:Magnoliopsida / Q000737:chemistry*; D008697:Methane / Q000096:biosynthesis*; D008892:Milk / Q000737:chemistry; D009753:Nutritive Value; D010636:Phenols / Q000378:metabolism*; D018515:Plant Leaves; D006109:Poaceae / Q000737:chemistry; D012417:Rumen / Q000378:metabolism*; D012418:Ruminants; D012621:Seasons
chemical_list: D010636:Phenols; D008697:Methane