水分含量对杂交臂形草青贮品质的影响

Effects of moisture content on silage quality of Brachiaria hybrid

试验旨在探究不同水分含量对杂交臂形草(Brachiaria hybrid)青贮品质的影响。试验以莫拉特Ⅱ杂交臂形草为青贮原料,设置35.0%、45.0%、55.0%、65.0%和70.4%(CK)5个含水量水平,进行青贮试验,常温条件下贮存60 d,开封后取样检测其青贮品质和营养品质。结果显示:随着青贮原料含水量的下降,青贮饲料的pH值、感官品质、粗脂肪、粗蛋白、粗灰分和可溶性碳水化合物含量均总体呈现先上升后下降的趋势,中性洗涤纤维含量总体呈现上升趋势,酸性洗涤纤维含量呈现逐渐降低的趋势。与CK相比,各处理组青贮饲料的氨态氮/总氮(NH3-N/TN)及丙酸、丁酸的含量显著降低(P<0.05),乳酸、乙酸和粗蛋白的含量显著增加(P<0.05)。原料含水量为45.0%~55.0%时,青贮饲料的pH值为4.08~4.10,感官品质最佳,为1级优等青贮饲料。研究表明,原料含水量对青贮饲料常规营养成分含量有一定影响,影响较大的指标是粗蛋白和粗脂肪含量,建议莫拉特Ⅱ杂交臂形草青贮原料的含水量应控制在45.0%~55.0%之间。

The purpose of this experiment was to investigate the effect of moisture content of different raw materials on the silage quality of Brachiaria hybrid.MoratⅡBrachiaria hybrid was used as silage material.The moisture content of MoratⅡBrachiaria hybrid was 35.0%,45.0%,55.0%,65.0%,and 70.4%(CK).The silage was stored at room temperature for 60 days.After opening,samples were taken to test its silage quality and nutritional quality.The results showed that the pH value,sensory quality,crude fat,crude protein,crude ash and soluble carbohydrate contents of silage all increased at first and then decreased with the decrease of moisture content of silage raw materials,while the content of neutral detergent fiber increased and the content of acid detergent fiber decreased gradually.Compared with CK,the ratio of NH3-N/TN,propionic acid,and butyric acid contents of silage in each treatment group decreased significantly(P<0.05),while lactic acid,acetic acid,and crude protein contents increased significantly(P<0.05).When the moisture content of raw materials is 45.0%~55.0%,the pH value of silage was 4.08~4.10,and the sensory quality was the best,which was a first-class excellent silage.The study indicates that the moisture content of raw materials has a certain influence on the content of conventional nutrients in silage,and the contentrations of crude protein and crude fat have great influence.It is suggeste that the moisture content of raw materials of MoratⅡBrachiaria hybrid silage should be controlled between 45%.0 and 55.0%.