摘要
试验选用3只装有瘤胃瘘管的浏阳黑山羊,采用体外发酵产气技术研究不同生育期虎尾草(Chloris virgata)体外模拟瘤胃发酵的72h累积总产气量以及0、2、4、6、8、10、12、24、36、48、72h甲烷产量,发酵液中72h的挥发性脂肪酸(Volatile Fatty Acid,VFA)和氨氮(NH3-N),以及72h干物质消失率。结果表明,不同生育期虎尾草的灰分(Ash)、粗蛋白(Crude protein,CP)、中性洗涤纤维(Neutral Detergent Fiber,NDF)、酸性洗涤纤维(Acid Detergent Fiber,ADF)含量差异显著(P<0.05)或极显著(P<0.01),Ash、CP含量随着生育期的延长而逐渐降低,NDF、ADF含量则呈逐渐增加趋势;随着生育期的延长,总产气量、甲烷的理论最大产气量(VF)以及72h干物质消失率均呈逐渐降低的趋势,其中各生育期间总产气量的VF差异不显著(P>0.05),幼苗期、拔节期、抽穗期、开花期、成熟期间甲烷产气量的VF也差异不显著,但均极显著高于干枯期样品(P<0.01),成熟期、干枯期间的72h干物质消失率极显著低于其余几个生育期(P<0.01);发酵液中NH3-N、总VFA以及乙酸浓度的变化趋势为"降低-增高-降低"趋势。综合考虑虎尾草各生育期所含营养成分以及体外发酵的产气特性,建议虎尾草在抽穗至开花期间进行刈割利用。
Three Liuyang black goats fitted with ruminal cannulas were used in this study. Various indices were evaluated including 72 h total cumulative gas production, 0, 2, 4, 6, 8, 10, 14, 24, 36, 48, 72 h methane yield, both degradation rate of dry matter and concentrations of volatile fatty acid profile and ammonia N of Chloris virga- ta at different growth stages in vitro fermentation after 72 h. The result showed that significant （P〈0. 05） or highly significant （P〈0.01） differences existed in Ash, crude protein（CP）, neutral detergent fiber （NDF）.acid detergent fiber （ADF） levels between different growth stages. Compositions of CP and ash decreased and levels of NDF and ADF increased with the maturity. The VF of total cumulative gas production, methane yield and 72 h dry matter disappearance rate decreased with harvests prolonged. The growth staged did not affect the VF of total cumulative gas production （P〉0.05） because VF of methane yield during turning green, j ointing, earing, flowering and maturity stage were not significantly different although they were significantly higher than withering stage. The 72 h dry matter disappearance rate during maturity, withering stage was significantly lower than that in the former growth periods. The concentrations of ammonia N, volatile fatty acid and acetic acid decreased andincreased followed by decreased again. According to the changes of nutrients and fermentation gas production characteristics in vitro, it＇s recommended that C. virgata should be harvested at the stage between earing to flowering.
出处
《草业科学》
CAS
CSCD
北大核心
2014年第5期956-964,共9页
Pratacultural Science
基金
973计划前期研究专项(2012CB22202)
关键词
虎尾草
生育期
营养成分
体外发酵产气特性
Chloris virgata
growth stage
nutritional component
in vitro fermentation characteristics ofgas production
