黄土高原不同撂荒年限草地中紫花苜蓿营养价值波动性研究

为明确紫花苜蓿营养价值随生长年限的变化规律,以黄土高原撂荒第4、5、6、8、12、13、14、15年草地的紫花苜蓿为研究对象,采用近红外光谱技术,测定其基本养分、矿物质和消化特性等,并对其营养价值进行评价。结果表明:不同撂荒年限草地的紫花苜蓿营养价值指标,除Ca、Mg、RFV(相对饲喂价值)变异系数较大外(10%~14%),其他指标的变异系数均较小(<9%),不同撂荒年限草地紫花苜蓿的粗蛋白含量均>19%,撂荒第14年和第15年草地的紫花苜蓿符合特级苜蓿干草制作标准,撂荒第5年和第6年草地的紫花苜蓿符合二级苜蓿干草制作标准,而其他撂荒年限草地的紫花苜蓿均符合一级苜蓿干草制作标准。综上,不同撂荒年限草地的紫花苜蓿营养价值均相对稳定,且为高品质牧草。

Nutritive Value Variation among Alfalfa(Medicago Sativa L.) on Grassland with Different Abandoned Years on the Loess Plateau

In order to clarify the nutritional variation of alfalfa with growth years,alfalfa on the abandoned grassland with the4 th,5 th,6 th,8 th,12 th,13 th,14 th and 15 th year on the Loess Plateau was selected as subject.Basic nutrient composition,mineral nutrients,digestive properties and nutritional value was detected by using near-infrared spectroscopy method.The results showed that variation parameters were small(<9%)excluding that of Ca,Mg and RFV which were between 10% and 14%.CP content of all alfalfa samples were more than 19%,alfalfa from the 14 th and 15 th years’ abandoned grassland meets the standard of super-grade alfalfa hay standard,alfalfa from the 5 th and 6 th years’ abandoned grassland meets the second-grade hay standard,and others could be classified into the first-grade hay production category.It was concluded that alfalfa nutritional quality would not be affected by the utilization year.