Chemical composition, digestibility in vitro and biodegradability of grass hays oven-treated with different amounts of ammonia

摘要: Abstract This study examined the effects of thermo-ammoniation (0, 15, 25 or 35 g ammonia kg−1 dry matter (DM) on chemical composition, organic digestibility in vitro (OMD[vt]) and cell wall degradability by cellulase (CWD) cocksfoot, ryegrass timothy hays, each prepared at three stages plant maturity. For variety, absolute increases total nitrogen, nitrogen soluble non-ammonia response to ammoniation were large, similar magnitude between varieties cuts. However, incremental small for applications above 15 DM. In contrast, concentrations 4-methylimidazole were, with one exception, more than doubled when treatment was raised from DM, related amount water carbohydrate (WSC) untreated hays. Each increment stimulated release aromatic compounds (principally phenolic acids) walls. OMD[vt] most strongly influenced CWD proportions undegradable walls, walls (percentage variance accounted (VAR) = 74, 79, 59 62 respectively). Of constituents, closely p-coumaric acid acids (VAR=69 68% The validity using gravimetric methods determine ammoniated hays can however be questioned. To limit production potential toxins, it is suggested that should restricted crops a low content WSC, applied minimal amounts, commensurate requirements preservation upgrading under relatively temperature conditions.