ABSTRACTS In the central Ethiopian highlands, the success or failure of livestock production was determined by livestock-environment interaction impacts which are mainly associated with overgrazing and land degradation (Endale, 2015). However, the differences of in vitro methane emission from free grazing and area closure is not studded & well documented. This study was conducted with the objective of assessing the effect of free grazing on forage quality and in vitro methane emission to fill this gap in sululta district.
The research followed mixed approach collecting data both primary (HH survey, FGD, KII and biomass survey) data, secondary data and 30 year RF and temperature data form metrological agency The data obtained from field survey of 139 HH respondents, 30 year RF and Temp data from meteorological agency and 90 sample biomass measurements collected from three kebeles (NMA, WL and WG). The data analysis employed survey data were analyzed by descriptive statistics using SPSS 21 version, metrological data analyzed in time serious using Minitab 17 version, farming system characterized using importance index and methane emission determined through laboratory at end of 24 incubation in which 1N Na (OH) 2 was added to the substrate of each syringes. Result showed, the mean annual rainfall of the study area was 1038.9mm and showed a decreasing trend with (1.251mm/year) with coefficient variation CV 29.48%. The mean minimum temperature of the study areas was 12.40C & showed an increasing trend by 0.14970C/decades. The farming system of the study area was characterized by mixed livestockcrop production system. Livestock feed balance of the study area was showed -36,000.45 ton deficit. The chemical analysis of animal feed was made according to Menke and Steingass as described by Abdulrazak and Fujihara, 2000 methods of analysis. The chemical composition of grass form area closure result was showed, OM 79.4%, CP 13.99%, ME 9.5Mj/kg DM, GP 42.78% and OMD 78.9 and DM 89.4%, Ash 15.3%, NDF61.73%, ADF29.38 %, ADL 2.98, and CH4 9.61%. The chemical composition of grass from free grazing result was showed OM 72.92%, CP 8.04%, ME 6.95 mg/kg DM, GP 37.56% and OMD 69.32 and DM 96.97%, Ash 19.15%, NDF78.51%, ADF45.33%, ADL7.79%, CH4 15.4%. This indicated that potential of methane production, higher in free grazing due to low forage quality caused by overgrazing/land degradation. To alleviate feed shortage different development options such as climate-smart technology such as development of improved forages with the use of irrigation and rain fed, Destocking to decrease the number of livestock down to the carrying capacity of the land, to control land degradation due to overgrazing and regional government give a value equal to communitybased water shade management strategy.
Keywords: Climate change, Digestibility, Dry matter, Metabolize energy,
