Production technology and quality of corn silage for feeding dairy cattle in Southern Brazil

ABSTRACTThe objective of this study was to evaluate the production practices and use of corn silage in dairy farms in Southern Brazil, and to evaluate their impact on the nutritional quality and occurrence of mycotoxins. The data were collected by application of questionnaires among the producers, and by analysis of silage samples. The variables were subjected to factorial analysis of data reduction through the principal components method, thus obtaining 84.12% of the variance associated with the location, corn hybrid, crop production management, and inoculant used, characterizing the farms into four distinct groups. In farms from Paraná, the silage production technologies were more associated with implantation and crop management processes, and investment in equipment related to ensilage/silo feed-out was less frequent. Farms of Rio Grande do Sul showed high adoption of outsourced services, self-propelled machines, bunker silos, double-sided plastic film, and inoculant to control aerobic deterioration, and the silages showed higher levels of propionic acid (7.95 g/kg DM), and lower concentrations of aflatoxins (7.7 ppb) and total mycotoxins (26.58 ppb). The farms evaluated in Southern Brazil have good production efficiency and corn silages with excellent quality, regardless of their production characteristics.

摘要：本研究旨在评估巴西南部奶牛场的玉米青贮（corn silage）生产实践与使用现状，并探究其对青贮营养品质及真菌毒素(mycotoxins)污染发生情况的影响。数据通过向养殖户发放问卷调研及青贮样品实验室检测两种方式采集。针对相关变量，本研究采用主成分分析法(principal components method)开展数据降维因子分析，最终得到与场地、玉米杂交品种、作物生产管理模式及所用接种剂(inoculant)相关的84.12%方差贡献率，并据此将受访养殖场划分为4个不同群组。在巴拉那州（Paraná）的养殖场中，青贮生产技术更多与种植定植及作物管理流程相关，而针对青贮制备与饲料卸料相关设备的投资则相对少见。南里奥格兰德州（Rio Grande do Sul）的养殖场则广泛采用外包服务、自走式机械、壕沟青贮窖、双面塑料膜以及用于控制好氧变质的接种剂，其生产的青贮产品丙酸含量更高（7.95 g/kg干物质(DM)），黄曲霉毒素(aflatoxins)浓度更低（7.7 ppb），总真菌毒素含量为26.58 ppb。本次评估的巴西南部养殖场均具备良好的生产效率，其产出的玉米青贮品质优异，不受自身生产特征差异的影响。