Chemical-bromatological composition and in vitro ruminal kinetics of sugar cane silage with maniçoba

ABSTRACT. The objective this study was to evaluate the effect of maniçoba supplementation in sugar cane silage with respect to chemical-bromatological composition and the in vitro degradation kinetics of the silage. This experiment was conducted in a completely randomized design with four treatments (maniçoba levels: 0, 20, 30, and 40%) and six repetitions. Silage samples were analyzed for their chemical-bromatological composition, digestible energy, metabolizable energy, total digestible nutrients, in vitro gas production and degradability parameters. The silage with higher inclusion level had better bromatological composition (p < 0.05) than the silage without maniçoba for CP, NDF, ADF and MM (6.49, 56.64, 38.66 and 4.52% versus 2.21, 70.96, 49.95 and 2.78%). Higher ME content (2.35 MJ kg-1 MS versus 1.85 MJ kg-1 MS), DE (2.87 Mcal kg-1 MS versus 2.25 Mcal kg-1 MS) and TDN (65.16% versus 51.11%), respectively. The highest values for gas production were also observed in silage with added maniçoba due to higher NFC content (34.87%). With an increase in the proportion of maniçoba, there was an increase in the soluble a fraction, b fraction, and thus a higher effective degradability of dry matter (46.56%). The addition of maniçoba improves the nutritive value of sugarcane silage.

摘要 本研究旨在评估在甘蔗青贮饲料中添加木薯副产品（maniçoba）对其化学-饲用营养组成及体外降解动力学的影响。本实验采用完全随机设计，设置4个处理组（木薯副产品添加水平分别为0%、20%、30%、40%），每组设置6次重复。对青贮饲料样品进行了化学-饲用营养组成、消化能（DE）、代谢能（ME）、总可消化养分（TDN）、体外产气量及降解参数的测定分析。结果表明，与未添加木薯副产品的青贮饲料相比，添加水平较高的处理组其粗蛋白（CP）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）及灰分（MM）的营养组成更优（P < 0.05），分别为6.49%、56.64%、38.66%和4.52%，而未添加组依次为2.21%、70.96%、49.95%和2.78%。添加组的代谢能（ME）、消化能（DE）及总可消化养分（TDN）含量均显著更高，分别为2.35 MJ·kg⁻¹干物质（MS）与1.85 MJ·kg⁻¹干物质（MS）、2.87 Mcal·kg⁻¹干物质（MS）与2.25 Mcal·kg⁻¹干物质（MS）、65.16%与51.11%。添加木薯副产品的青贮饲料产气量也更高，这与其非纤维碳水化合物（NFC）含量较高（34.87%）直接相关。随着木薯副产品添加比例的提升，青贮饲料的可溶性a组分、b组分含量均有所增加，进而使干物质有效降解率升高至46.56%。综上，在甘蔗青贮饲料中添加木薯副产品可显著提升其饲用营养价值。