巨菌草不同生长高度养分测定与刈割利用高度分析

Analysis on Nutrient Determination and Cutting Utilization Height of Pennisetum sp. at Different Growth Heights

摘要: 为了解巨菌草的牧用价值，笔者通过对40、80、120、160、200、240、280、320、360 cm下自然生长高度巨菌草的地上生物量、含水量、干物质和粗蛋白等养分指标测定，探索巨菌草作为牧用饲草的养分变化规律及适宜刈割利用高度。结果表明：巨菌草作为牧用饲草时，粗蛋白含量在生长高度40 cm时最高，为13.30%，在360 cm时最低，仅为4.32%，并随生长高度的增加而下降；干物质含量随生长高度的增加而增加，以360 cm时最高，为30.69%，40 cm时最低，为14.52%；水分含量变化则与干物质含量变化相反。因此，巨菌草作为牛、羊等草食家畜青绿饲草料鲜饲利用时，宜在120~160 cm高度时刈割利用；巨菌草作为牛、羊等草食家畜优质饲草料青贮加工利用时，宜在240~280 cm间刈割利用。是直接饲喂和加工利用的理想牧草之一。

Abstract: In order to understand the value of animal husbandry of Pennisetum sp., the nutrient indexes such as aboveground biomass, water content, dry matter and crude protein of Pennisetum sp. under 40, 80, 120, 160, 200, 240, 280, 320, 360 cm were measured to explore the nutrient change law and appropriate mowing height of Pennisetum sp. as forage grass. The results showed that the crude protein content of Pennisetum sp. was the highest at 40 cm, 13.30%, the lowest at 360 cm, only 4.32%, and decreased with the increase of growth height; the dry matter content increased with the increase of growth height, the highest at 360 cm, 30.69%, the lowest at 40 cm, 14.52%. The change of moisture content is opposite to that of dry matter content. Therefore, when Pennisetum sp. is used as fresh forage for cattle, sheep and other herbivorous livestocks, it should be mowing at 120 - 160 cm height, and when Pennisetum sp. is used in high-quality forage-silage processing and utilization for cattle, sheep and other herbivorous livestocks, it should be mowing at 240 - 280 cm height. Pennisetum sp. is one of the ideal forages for direct feeding and processing and utilization of forages.