Abstract:

The effects of lactic acid bacteria and cellulase on the silage quality of Napier grass silages were assessed in this study. Napier grass at heading stage was harvested, then treated with 0.1 g·kg^-1cellulase (CEL), 10⁶ cfu·g^-1 lactic acid bacteria inoculants (LD1～LD8) and 10⁶ cfu·g^-1lactic acid bacteria inoculants +0.1 g·kg^-1 cellulase (LD1+CEL～LD8+CEL), respectively. Each treatment had three replications. The fermentation qualities and chemical compositions of silages were tested after 60 days. Results showed that Napier grass silages were improved by the addition of bacteria and cellulase alone or together due to the lower pH value, butyric acid content (P<0.05). The lactic acid and crude fat (EE) contents of treated silages were higher than CK(P<0.05). The Fleig evaluation of Napier grass silage showed that the fermentation qualities of silages added LD2, LD3 and LD7 were excellent, followed by the fermentation quality of LD4. The NDF and ADF contents of silages added both bacteria and cellulase were lower than CK, while the WSC contents were higher than CK. The silages added CEL+LD6 had the lowest NDF and ADF contents, and the highest WSC content (P<0.05). Therefore, The CEL+LD6 had the best effect on both fermentation quality and chemical compositions. The nutrition values of the silages were improved.

Key words: Napier grass, Lactic acid bacteria, Cellulase, Silage quality

摘要：

以象草(Pennisetum purpureum)为材料,研究了乳酸菌和纤维素酶单独添加或组合添加对象草青贮发酵品质和营养价值的改善效果.象草经刈割切短后,分别添加纤维素酶(CEL)、乳酸菌(LD1～LD8)、乳酸菌+纤维素酶(LD1+CEL～LD8+CEL),密封贮藏60 d后测定青贮饲料的发酵品质和营养价值.结果表明:所有添加剂处理组的pH值、丁酸含量均显著低于对照组(CK),乳酸、粗脂肪(EE)含量均显著高于对照组(P<0.05).弗氏法评分中LD2,LD3,LD7及所有组合添加处理组的发酵品质均为优,LD4发酵品质为中,CK发酵品质为差.组合添加处理组的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量均显著低于CK(P<0.05),可溶性碳水化合物(WSC)均显著高于CK;且LD6+CEL将青贮饲料的NDF,ADF降到最低,其WSC也显著高于各处理组(P<0.05).表明添加乳酸菌、纤维素酶能有效改善象草青贮的发酵品质和营养价值,且以LD6+CEL的青贮效果最好.

关键词: 象草, 乳酸菌, 纤维素酶, 青贮品质