Macauba palm cake as additive in elephant grass silage

ABSTRACT. The aim of this study was to evaluate the addition of macauba palm cake (Acrocomia aculeata) on the chemical composition, fermentation and aerobic stability of elephant grass silages (Pennisetum purpureum). The experiment was performed in a completely randomized design with four replicates. The treatments were composed of six levels of macauba palm cake (0, 6, 12, 18, 24, 30%) as additive to elephant grass silage. Dry matter and ethereal extract content of the silage increased linearly with the inclusion of the additive. Addition levels of 15.54% would provide 35% of dry mass, and the limit of 7.00% of ethereal extract in the silage could be obtained with 10.47%. The neutral detergent fiber content reduced linearly from 68.97 to 52.59%, but lignin increased linearly from 6.56 to 7.70%. There was a reduction of 0.17% in the ammoniacal nitrogen content for each 1% of cake. The minimum value of dry matter losses (1.33%) was estimated to the inclusion level of 23.70%. The aerobic stability increased with inclusions between 18 and 24% of cake. The use of levels between 10 and 15% of macauba palm cake are sufficient to optimize dry matter and ethereal extract contents of the silages and to provide a high aerobic stability with minimum losses.

摘要：本研究旨在评估添加刺果棕（Acrocomia aculeata）饼粕对象草（Pennisetum purpureum）青贮料的化学成分、发酵特性及有氧稳定性的影响。本实验采用完全随机设计，设置4次重复。处理组以6个不同添加水平（0%、6%、12%、18%、24%、30%）的刺果棕饼粕作为象草青贮的添加剂。青贮料的干物质（dry matter）与乙醚浸出物（ethereal extract）含量随添加剂添加量的增加呈线性升高。当添加水平为15.54%时，青贮料干物质占比可达35%；而当青贮料乙醚浸出物含量达到7.00%的限值时，对应的饼粕添加量为10.47%。中性洗涤纤维（neutral detergent fiber）含量从68.97%线性降低至52.59%，但木质素（lignin）含量则从6.56%线性升高至7.70%。每添加1%的刺果棕饼粕，青贮料的氨态氮（ammoniacal nitrogen）含量可降低0.17%。经估算，当饼粕添加水平为23.70%时，干物质损失（dry matter losses）达到最小值（1.33%）。当饼粕添加量介于18%~24%之间时，青贮料的有氧稳定性（aerobic stability）随添加量提升而增强。使用10%~15%的刺果棕饼粕添加水平，即可优化青贮料的干物质与乙醚浸出物含量，同时实现较高的有氧稳定性且干物质损失最小。