Quantifying Herbage Mass, Composition and Feed Value of Grass Land as Influenced by Altitude in Western Highlands of Ethiopia

Abstract

Assement on the status of florisic composition, Biomass and Nutritive value of grass land was conducted in highland and mid altitude areas of Horro and Guduru districts with the objectives of assessing the present status of grazing lands interms of quality and quantity. The study was conducted during the last week of September to the first week October 2014 when much of herbs starts to flower. A total of 25 herbs were identified from grazing lands of the study area, of these 17 grass species (5 annuals and 12 perennial ), 3 legume species, 2 sedges and 4 weeds species were identified in both agro ecologies except one grass (Eleusine africana) which was only observed in mid altitude area. Most of grass species were prennials. The herbage yield of grass lands of highland was 2.52 ton per hectare while, that of mid highland was 2.73 t/ha and these were not significantly different (P>0.05). The compositions of grasses, legumes and weed and or sedges were 69.6, 28.7 and 2.18 percent respectively for highland while in mid highland it was 73.6, 25.6 and 0.8 percent respectively. The ash content of mid altitude composite herbs (16.9±0.02) was significantly higher (P<0.001) than that of highland samples (9.21±0.1).  There were no significant differences in crude protein (CP) content herbs harvested between the two agro ecologies.The neutral detergent fiber (NDF) content of mid altitude herb (61.7±.09) was significantly higher (P<0.001) than (54.8±0.07) percent reported for highland and  Adltitude. The in vitro dry matter digestibility (IVDMD) and metabolisable energy (ME) content of harvested highland herbs were significantly higher (P<0.01) than that of mid altitude while there were no significant difference in digestible crude protein (DCP) of herbs between the two agro ecologies.The dry matter digestibilities (DDM) of highland herbs were significantly higher than the mid altitude herbs. Similarily estimated dry matter intake (DMI) and relative feed value (RFV) of samples of herbs of highland were significantly higher (P<0.001) than that of mid altitude. The nutritive value of herbage harvested at flowering stage in the present study agro ecology generally indicate well in supplying basic nutritional requierement of livestock but, the low potential yield of the grass lands should be the area of intervention in both highland and mid altitude.

Keywords: Annuals, Herbage yield, Nutrient composition, Prenials