Untreated or ammoniated cotton gin trash in the ensiling of elephant grass reduces silage quality

ABSTRACT. This study examined the inclusion of untreated or urea-ammoniated CGT on the chemical composition, pH, gas, and effluent losses, dry matter recovery (DMR), and aerobic stability of elephantgrass silage. The experiment was laid out in a randomized design with a 3 × 3 factorial arrangement represented by three levels of inclusion of CGT during ensiling (0, 5, or 10%) and three levels of ammoniation of CGT with urea before ensiling (0, 4 or 8% for 28 days), using four replications. Data were subjected to analysis of variance and Tukey's test, considering a 5% significance level. The pH and DM, NDIN, ADIN, NDF and ADF contents of the silages increased (p < 0.05) with the inclusion of CGT, regardless of ammoniation. The lowest (p < 0.05) effluent loss was achieved using 10% of CGT ammoniated with 8% urea. In contrast, the elephantgrass silage exhibited the lowest (p < 0.05) gas loss and the greatest (p < 0.05) DMR. The inclusion of CGT compromised the aerobic stability of the silage. Therefore, the inclusion of CGT - either untreated or ammoniated - in the ensiling of elephantgrass is not recommended.

摘要。本研究探讨了未处理或经尿素氨化的CGT（CGT）对象草青贮料（elephantgrass silage）的化学组成、pH值、气体损失、流失液损失、干物质回收率（dry matter recovery, DMR）以及好氧稳定性（aerobic stability）的影响。本试验采用3×3因子设计的随机试验方案，设置两个处理因素：一是青贮过程中CGT的添加水平（0、5%或10%），二是青贮前用尿素对CGT进行氨化的处理水平（0、4%或8%，处理时长28天），每组设置4个生物学重复。试验数据经方差分析（analysis of variance）与Tukey多重比较检验进行统计分析，显著性水平设定为5%。结果表明，无论是否经过氨化处理，随着CGT添加量的提升，青贮料的pH值、干物质（dry matter, DM）、非蛋白氮（non-protein nitrogen, NDIN）、酸不溶氮（acid detergent insoluble nitrogen, ADIN）、中性洗涤纤维（neutral detergent fiber, NDF）与酸性洗涤纤维（acid detergent fiber, ADF）含量均显著升高（p < 0.05）。当添加10%经8%尿素氨化的CGT时，青贮料的流失液损失最低（p < 0.05）。与之相比，未添加CGT的象草青贮料的气体损失最低，且干物质回收率最高（二者p均<0.05）。CGT的添加会降低青贮料的好氧稳定性。因此，不建议在象草青贮过程中添加未处理或经氨化处理的CGT。