纤维素酶和木聚糖酶对象草青贮发酵品质及体外消化率的影响

Effects of Cellulase and Xylanase on Fermentation Quality and in Vitro Digestibility Coefficient of Napier Grass

为探讨纤维素酶和木聚糖酶对象草(Pennisetum purpureum Schumach)青贮发酵品质与体外消化率的影响,试验设对照组(CK)、添加纤维素酶组(CE)、添加木聚糖酶组(XE)和组合添加酶组(CX,纤维素酶+木聚糖酶)。青贮7,30,60,90 d后开窖取样,测定相关指标。结果表明:与对照组相比,CE,XE和CX组显著提高了乳酸含量(P<0.05),降低了pH、氨态氮/总氮和干物质损失;添加酶处理组中性洗涤纤维(Neutral detergent fiber,NDF)、酸性洗涤纤维(Acid detergent fiber,ADF)、纤维素、半纤维素含量均低于对照,并且水溶性碳水化合物、葡萄糖、果糖和蔗糖含量增加;体外发酵试验中,CE,XE和CX组青贮饲料干物质消化率、中性洗涤纤维消化率、酸性洗涤消化率和体外产气均显著高于CK(P<0.05),且CX组体外产气量最高,而CE与XE之间差异不显著。综上,添加纤维素酶、木聚糖酶提高了象草青贮发酵品质与体外消化率,组合添加酶效果更好。

To explore the effects of cellulase and xylanase on the fermentation quality and in vitro digestibility coefficient of napier grass(Pennisetum purpureum Schumach)silage,the napier grass was ensiled with no additive control(CK),cellulase(CE),xylanase(XE),combined addition(CX cellulase+xylanase),respectively.The silos were opened after 7,30,60 and 90 days of ensiling to analyse fermentation quality.The results showed that CE,XE or CX addition significantly increased lactic acid content(P<0.05),reduced pH,ammonia nitrogen/total nitrogen and dry matter loss.The contents of neutral detergent fiber,acid detergent fiber,cellulose and hemicellulose of enzyme addition treatments were lower than those of CK,while the contents of water-soluble carbohydrates,glucose,fructose and sucrose were higher than CK.In the in vitro fermentation test,the dry matter digestibility,neutral detergent fiber digestibility,acid detergent digestibility and in vitro gas production of CE,XE and CX silages were significantly higher than CK(P<0.05).The CX had the highest in vitro gas production(P<0.05),and there was no significant difference between CE and XE.In summary,the addition of cellulase and xylanase can improve the fermentation quality and in vitro digestibility of napier grass silage,and the combined addition effect is better.