Elephant grass silage with addition of regional by-products

ABSTRACT. This study examines the effect of adding coffee husks (CH), cacao by-product (CBP) and passion fruit by-product (PBP) (fresh-matter basis) in the silage of elephant grass cv. Napier on nutritional characteristics. The experiment was laid out in a completely randomized design with a 3 × 4 factorial arrangement represented by three additives (CH, CBP or PBP) and four inclusion levels (0, 12, 24 or 36%). Four replicates were used per treatment. The material was ensiled in experimental mini-silos that were opened 60 days later for chemical analysis of the produced silages. The dry matter content of the silages with CH and PBP included at levels greater than 25% was adequate. The silage with PBP inclusion showed the highest crude protein levels and the best results for in vitro dry matter digestibility. In the silage containing CH, the neutral detergent fiber content decreased linearly with increasing inclusion of the husks. The silage with CBP showed the lowest dry matter and crude protein levels and the highest pH. In conclusion, the inclusion of up to 36% PBP in the ensiling of elephant grass is recommended, as the resulting material has potential for use in ruminant feeding at times of forage scarcity.摘要。本研究考察了以鲜重为基准添加咖啡壳（coffee husks, CH）、可可副产物（cacao by-product, CBP）与百香果副产物（passion fruit by-product, PBP）对纳皮尔象草（elephant grass cv. Napier）青贮饲料营养特性的影响。本实验采用3×4因子排列的完全随机设计，设置3种添加剂（CH、CBP或PBP）与4种添加水平（0、12%、24%或36%），每个处理设置4次生物学重复。试验原料被装填于实验用微型青贮窖（mini-silos）中，于60天后开封，对制备得到的青贮饲料开展化学分析。添加CH与PBP且添加量高于25%的青贮饲料，其干物质含量（dry matter content）符合标准要求。添加PBP的青贮饲料粗蛋白（crude protein）含量最高，且体外干物质消化率（in vitro dry matter digestibility）表现最优。在添加CH的青贮饲料中，中性洗涤纤维（neutral detergent fiber）含量随壳类添加量提升呈线性下降趋势。添加CBP的青贮饲料干物质与粗蛋白含量最低，且pH值最高。综上，推荐在纳皮尔象草青贮过程中添加最高达36%的PBP，所得饲料在饲草短缺时期具备用于反刍动物饲喂的应用潜力。