Tibbo, Markos (PhD)Dagne, Kifle (PhD)Nigussie, Kidus2018-07-032023-11-082018-07-032023-11-082010-11http://etd.aau.edu.et/handle/123456789/5837The major objectives of this work were to assess the utilization and management condition of crossbred and indigenous goats and to develop a biophysical model for crossbred goats. A survey was made in three districts (Kombolcha, Gursum and Konso) in Eastern and Southern Ethiopia to assess the utilization of these goats. In addition, a three-year data was obtained from Haramaya University to develop the biophysical model. Nearly 92% of the respondents prefer crossbred goats to indigenous goats. These respondents prefer crossbred goats due to the physical, productive, and reproductive features of the crossbred goats compared to the indigenous goats. However, in terms of ability to walk long distance, longevity and disease tolerance, local goats were preferred by most of the farmers than the crossbred goats. For milk and meat production crossbred goats were their first choice than local goats. The most common method of grazing crossbred goats was tethering. About 74% of Kombolcha, 86% of Gursum and 94% of Konso district respondents feed their crossbred goats through tethering. The amount of dry matter (DM) protein supplement was the major factor affecting productivity of crossbred goats. The amount of protein supplement given to the crossbred goats affected longevity, daily milk yield and lactation length. Crossbred had higher milk yield and longer lactation length than indigenous goats but they suffered higher mortality. In the districts an average of 3.17 family labors was used per flock. Most of the crossbred goat owners practiced controlled breeding. Goats’ health care was found to be one of the most important factors that affect the productivity of crossbred goats. Increased investment (expenditure) for medical cases was found to increase the longevity of goats, milk yield and lactation length of the goats. Information generated in this study is believed to guide investment priorities for in goat-keeping families in the country. Six models developed using a three year data. To develop these models a total of 165 crossbred goats and 257 indigenous (Somali breed) goats included in the study. To fit the models a total of 20,907 daily record of the crossbred goats are used. �� Weight = -1.17 + 28.723*Feed Intake+ 12.619*Labor intake of each of goat The model shown above is used to estimate the performance of crossbred goats in the three districts and can be used to estimate the weight of a crossbred goat if the other variables are known or vice versa. Key words: Gursum district, Kombolcha district, Konso district, Haramaya University, crossbred goats, simulation model, indigenous goatsenGursum districtKombolcha districtKonso districtHaramaya Universitycrossbred goatssimulation modelindigenous goatsThesis