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The chemical composition, digestibility and energy value of fermented and urea‐treated whole crop wheat harvested at three stages of maturity
Author(s) -
Adesogan A. T.,
Owen E.,
Givens D. I.
Publication year - 1998
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1046/j.1365-2494.1998.00105.x
Subject(s) - dry matter , urea , chemistry , forage , organic matter , zoology , starch , composition (language) , agronomy , fermentation , food science , chemical composition , formic acid , biology , biochemistry , linguistics , philosophy , organic chemistry
The metabolizable energy (ME) content, digestibility in vivo and chemical composition of fermented and urea‐treated whole crop wheat (WCW) forage harvested were measured at different maturities. Over 2 years, twenty‐four wheat forages (cv. Slepjner, Hussar and Cadenza) were harvested at 376, 516 and 632 g dry matter (DM) kg −1 in Year 1 and 341, 467 and 544 g DM kg −1 in Year 2 (Cuts 1, 2 and 3 respectively). Forages were conserved in 200−‐ι barrels with or without a formic acid‐based additive and with urea in Cuts 2 and 3 (20 or 40 g kg −1 DM). Chemical compositions, digestibility in vivo and energy losses in faeces, urine and methane were measured in wethers fed 12 g DM kg −1 live weight. Respective ranges in pH, crude protein, water‐soluble carbohydrates, starch and neutral detergent fibre plus amylase (NDFA) contents were 3·8–8·5, 89–394, 2–43, 23–424 and 306–655 g kg −1 DM. ME content, digestible organic matter content (DOMD) and digestibilities of starch and NDFA ranged between 8·4 and 15·7 MJ kg −1 DM, 558 and 708 g kg −1 DM, 0·901 and 0·999 and 0·362 and 0·693 respectively. Predicted methane energy losses were poorly correlated with measured values ( r 2 < 0·45) in both years, but this accounted for less than 0.1 MJ ME kg −1 DM. Significant ( P < 0.05) effects of maturity on the ME/DOMD ratio were observed and ascribed to differences in the extent of fermentation. Therefore, treatment application and maturity exert considerable influence on the ME content of WCW.