Quality of sorghum silage with leucaena

ASTRACT. This study evaluated the effect of increasing levels of leucaena forage in sorghum: forage. In addition to pure sorghum, it was evaluated different levels of inclusion of leucaena (15, 30 and 50%) at the time of ensiling. Forage was ensiled in PVC tubes (100 mm diameter, 500 mm length) under the density of 500 - 600 kg m-3, a total of 20 silos were prepared, which were opened 35 days after ensiling. There was no effect (p > 0.05) of leucaena inclusion levels for pH, water activity (Aw) and total ammonia nitrogen (total NH3-N). There was an increasing linear effect (p < 0.05) for the content of dry matter (DM), crude protein (CP) and lignin that increased from 33.47 to 34.75%, 7.82 to 16.05% and from 7.29 to 9.93%, at the levels from 0 to 50% inclusion of leucaena, respectively. There was a decreasing linear effect (p < 0.05) for neutral detergent fiber corrected for ash and protein (NDFcp) and hemicellulose, which reduced from 56.65 to 48.37% and from 24.07 to 17.67% at the levels of 0 and 50% inclusion, respectively. For the ash content, there was a quadratic effect (p < 0.05), with a maximum at 8.3% with 8.9% inclusion of leucaena. The inclusion of up to 50% leucaena into sorghum silage is recommended, because, in addition to maintaining the fermentation quality, it also improved nutritional quality of sorghum silage.

摘要。本研究评估了高粱（Sorghum）与银合欢（Leucaena）饲草配比梯度升高的影响。除纯高粱青贮外，本试验还评估了青贮时银合欢的不同添加比例（15%、30%和50%）的效果。试验将饲草装填于聚氯乙烯（PVC）管（直径100 mm，长度500 mm）中，装填密度为500~600 kg·m⁻³，共制备20个青贮单元，于青贮35天后开封。结果显示，银合欢添加比例对酸碱度（pH）、水分活度（Aw）及总氨氮（total NH3-N）无显著影响（p>0.05）。干物质（DM）、粗蛋白（CP）及木质素含量随银合欢添加比例从0提升至50%，分别从33.47%升至34.75%、7.82%升至16.05%、7.29%升至9.93%，呈现显著线性升高趋势（p<0.05）。校正灰分与蛋白质的中性洗涤纤维（NDFcp）及半纤维素含量则随添加比例升高呈显著线性降低趋势（p<0.05），分别从56.65%降至48.37%、24.07%降至17.67%。灰分含量呈显著二次效应（p<0.05），在银合欢添加比例为8.9%时达到峰值8.3%。研究建议在高粱青贮中添加最高50%的银合欢，此举不仅可维持青贮发酵品质，还可改善高粱青贮的营养品质。