Nutritional value and fermentative characteristics of pearl millet silage with different levels of coffee husk

ABSTRACT: The research was conducted to test the hypothesis that the inclusion of coffee husk (Coffea sp.) would improve the fermentative characteristics and quality of pearl millet silage (Pennisetumglaucum). Thus, the objective was to assess the effect of the inclusion of different levels of coffee husk in pearl millet silage on the chemical composition, fermentative characteristics and degradability in situ of silage. The experimental design used was completely randomized and the treatments consisted of the silage of the whole pearl millet plant with the inclusion of increasing levels of coffee husk: 0%, 7%, 14% and 21%, based on natural matter. After 60 days of fermentation, the silages were evaluated for chemical characteristics, fermentative, degradability in situ dry matter (DM) and neutral detergent fiber (NDF). The inclusion of coffee husk did not alter (P > 0.05) the contents of crude protein (11.94%), NDF (44.89%) and total digestible nutrients (65.09%). There were increases in the concentrations of DM and fiber in acid detergent, accompanied by a reduction in the concentrations of mineral matter and ether extract, as the proportion of coffee husks in silages increased. There was an increase in the lignin content up to the level of 7.59% inclusion of the coffee husk. There was no effect of the inclusion of the coffee husk on the pH of the silage (3.60). However, the inclusion of coffee husk resulted in a reduction in temperature, gas losses, and degradability in situ of silage DM and NDF. It is recommended to include coffee husk up to the level of 14.0% of the natural matter to improve the fermentation pattern and the quality of the pearl millet silage.

摘要：本研究旨在检验添加咖啡果壳（Coffea sp.）可改善珍珠粟青贮料（Pennisetum glaucum）发酵特性与品质这一假说。据此，本研究旨在评估在珍珠粟青贮料中添加不同梯度咖啡果壳，对其化学成分、发酵特性以及原位干物质（dry matter, DM）和中性洗涤纤维（neutral detergent fiber, NDF）降解率的影响。
本试验采用完全随机试验设计，试验组为全株珍珠粟青贮料，按自然物质基准添加梯度递增的咖啡果壳，添加比例分别为0%、7%、14%和21%。发酵60天后，对各青贮料的化学特性、发酵指标以及原位干物质和中性洗涤纤维降解率进行测定。
咖啡果壳的添加并未显著影响粗蛋白（11.94%）、中性洗涤纤维（44.89%）以及总可消化养分（65.09%）的含量（P > 0.05）。随着青贮料中咖啡果壳占比提升，酸性洗涤纤维含量显著升高，同时矿物质与乙醚提取物含量随之降低。当咖啡果壳添加比例达7.59%时，青贮料的木质素含量出现升高。
咖啡果壳的添加对青贮料的pH值无显著影响（均值为3.60）。但添加咖啡果壳可降低青贮料发酵温度、气体损失量以及原位干物质与中性洗涤纤维降解率。
本研究建议以自然物质为基准，将咖啡果壳的最大添加比例设为14.0%，以优化珍珠粟青贮料的发酵模式并提升其品质。