西藏青稞秸秆与多年生黑麦草混合青贮发酵品质的研究

本研究旨在将青稞秸秆与黑麦草以不同比例混合青贮,评价其发酵品质,筛选出适宜的混合比例。试验设青稞秸秆单独青贮(对照组)、80%青稞秸秆+20%多年生黑麦草混贮(L组)、60%青稞秸秆+40%多年生黑麦草混贮(M组)及40%青稞秸秆+60%多年生黑麦草混贮(H组)4个处理。青贮后第7,14和30天后打开青贮窖,测定青贮饲料发酵品质。结果表明,青稞秸秆与黑麦草混合青贮显著(P<0.05)提高了乳酸和水溶性碳水化合物含量,显著(P<0.05)降低了pH值和干物质含量,M和H组在乳酸产生的同时乙酸含量显著(P<0.05)提高,混贮组氨态氮/总氮略低于对照组(P>0.05),各组均显示较低的丙酸和丁酸含量。从秸秆利用最大化的角度出发,建议以40%黑麦草混合青贮较为适宜。

A study on fermentation quality of mixed silages of hulless barley straw and perennial ryegrass in Tibet

The fermentation quality of mixed silages of hulless barley (Hordeum vulgare) straw and perennial ryegrass (Lolium perenne) was studied using the following treatments: control (100% hulless barley straw), L (80% hulless barley straw+20% perennial ryegrass), M (60% hulless barley straw+40% perennial ryegrass) and H (40% hulless barley straw+60% perennial ryegrass). The laboratory silos were opened on 7, 14 and 30 days after ensiling in triplicate and the fermentation quality was measured. The mixed silages significantly (P<0.05) increased lactic acid and water soluble carbohydrate contents, while significantly (P<0.05) reducing pH value and dry matter content. Acetic acid content was significantly (P<0.05) increased with an increase of perennial ryegrass in mixed silages. The ammonia/total nitrogen of mixed silages was lower (P>0.05) than that of the control. There was little butyric or propionic acids in all silages. Based on these results, mixed silage of 40% perennial ryegrass was best for improving the fermentation quality of hulless barley straw.