title: Production, Nutritional Quality and In vitro Methane Production from Andropogon gayanus Grass Harvested at Different Maturities and Preserved as Hay or Silage.
abstract: Andropogon gayanus is an important grass due to its high biomass production, drought tolerance and favorable growth on low fertility acidic soils. Currently, there is little research on the impact of growth stage on the nutritional quality or the degree of CH4 production that may arise from this forage during ruminal fermentation. The objectives of this study were to determine the effects of regrowth stage of A. gayanus on its chemical composition, in vitro production of gas and CH4, as well as in vitro dry matter (DM) digestibility when grown under tropical Brazilian conditions and conserved as hay or as silage. The nutritional value of A. gayanus grass declined with increasing maturity; however digestible DM yield linearly increased. After 112 d of regrowth, A. gayanus produced higher quality silage (higher lactate and lower pH and butyrate content) and higher DM yield. However, the low levels of crude protein at this time would make protein supplementation a necessity for proper rumen fermentation. No differences in CH4 kinetic parameters were found with advancing maturity or preservation method (hay or silage).
authors: Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil ; Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada T1J 4B1.
authors: G O
authors: GO
authors: Ribeiro
authors: Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: A M
authors: AM
authors: Teixeira
authors: Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: F O
authors: FO
authors: Velasco
authors: Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: W G
authors: WG
authors: Faria Júnior
authors: Embrapa Gado de Leite - CNPGL, Coronel Pacheco, MG, Brazil .
authors: L G R
authors: LG
authors: Pereira
authors: Faculty of Veterinary Science, University of Sydney, Sydney, NSW, 2006, Australia .
authors: A V
authors: AV
authors: Chaves
authors: Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: L C
authors: LC
authors: Gonçalves
authors: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada T1J 4B1.
authors: T A
authors: TA
authors: McAllister
keywords: In vitro; Maturity; Methane; Rumen; Silage Quality; Tropical Grass