体外产气技术评价高原地区人工牧草营养价值研究

Evaluation of nutritional value of artificial grasses in plateau region by in vitro gas production technology

试验研究高原地区人工牧草营养价值。采用概略养分分析法和体外产气法测定青海省农牧交错区种植的黑麦草、披碱草、冰草、大麦、全株玉米以及黑燕麦6种人工牧草的牧草常规营养成分含量和体外发酵参数。结果显示,黑麦草、冰草钙(Ca)含量显著高于黑燕麦、全株玉米和大麦(P<0.05)。大麦的粗脂肪(EE)含量最高,全株玉米次之,两者均极显著高于其他人工牧草(P<0.01)。48h体外产气量(GP)与EE、粗蛋白(CP)含量呈显著正相关关系(P<0.05),其中全株玉米和大麦的48hGP极显著高于其他牧草(P<0.01)。体外干物质消化率(IVDMD)与牧草各常规营养指标之间不存在显著相关性(P>0.05),其中全株玉米的IVDMD极显著高于黑麦草、黑燕麦、披碱草和大麦(P<0.01)。研究表明,6种人工牧草中全株玉米的营养价值最好,饲草中粗蛋白与粗脂肪含量是影响饲草体外产气量的两个重要因素。

The experiment studied the nutritional value of artificial forage in plateau. The content of conventional nutrients and in vitro fermentation parameters of six kinds of artificial forage grasses including ryegrass, elymusnutans, ice grass, barley, whole-crop corn and black oats grown in Qinghai Province were determined by probabilistic nutrient analysis and in vitro gas production method. The results showed that the content of Ca in ryegrass and ice grass was significantly higher than that in black oats, whole-crop corn and barley(P<0.05). The content of EE in barley was the highest, followed by whole-crop corn, and both were extremely significantly higher than that of other forage grasses(P<0.01). The significantly positive correlations between 48 h GP and EE or CP were observed(P<0.05), and the 48 h GP of whole-crop corn and barley were extremely higher than that of other forage grasses(P<0.01). The IVDMDs were not significant correlative with the nutrient components of the forage grass(P>0.05), and the IVDMD of whole-crop corn was extremely higher than that of ryegrass, black oats, elymusnutans and barley(P<0.01). The experiment indicates that the quality of whole-crop corn among the six kinds of artificial forage grass is the best, and the contents of crude protein and crude fat are the two important factors affecting gas production in vitro.