ABSTRACT

Urban/peri-urban dairying in East Africa used to be typified by elephant grass (Pennisetum purpureum, Schumach) as the primary forage. However, the ever-declining space for farming has made forage cultivation increasingly difficult. As a coping strategy, farmers are harvesting vegetation biomass from natural environment, particularly common reed (Phragmites australis, Cav.) from wetlands. This study aimed to compare elephant grass and common reed in terms of chemical composition and in situ rumen degradation. Samples were collected (in dry and wet seasons) and analyzed for chemical composition, and in situ rumen degradation of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) determined. Rumen degradation was determined by incubating triplicate nylon-bagged samples in rumens of three cannulated Ankole–Friesian crossbred steers. The CP content ranged from 10.8% to 16.2% DM (common reed), and 9.9–12.5% DM (elephant grass). Common reed showed lower DM, and ADF compositions, and higher effective rumen degradability of DM, CP, and NDF in both seasons. For both forages, CP content was higher during the dry season, while effective rumen degradability of DM, CP, and NDF were higher in the wet season. In summary, the chemical and rumen degradation results suggest that common reed may be nutritionally superior to elephant grass.

摘要

东非的城市/城郊奶牛场过去主要以象草（狼尾草（Pennisetum purpureum，Schumach））为主要草料。但是，不断缩小的耕种空间使饲草的种植越来越困难。作为一种应对策略，农民正在从自然环境中收获植被生物量，特别是从湿地中收获常见的芦苇（芦苇）。这项研究旨在从化学成分和瘤胃原位降解方面比较象草和普通芦苇。收集样品（在干燥和潮湿的季节）并就地分析化学成分确定了瘤胃降解的干物质（DM），粗蛋白（CP）和中性洗涤剂纤维（NDF）。瘤胃降解是通过在三只插管的Ankole-Friesian杂交ste牛的瘤胃中孵育一式三份的尼龙袋装样品来确定的。CP含量范围为10.8％至16.2％DM（普通芦苇）和9.9–12.5％DM（大象草）。普通芦苇在两个季节中均表现出较低的DM和ADF成分，以及较高的DM，CP和NDF有效瘤胃降解能力。对于这两种牧草，在干燥季节中CP含量较高，而在潮湿季节中DM，CP和NDF的有效瘤胃降解率较高。总而言之，化学和瘤胃降解结果表明，普通芦苇在营养上可能优于象草。