You will develop a computer simulation model of diet selection and nutrient utilization by sheep and goats grazing succulent Karoo. This is a multidisciplinary project that will involve both some experimental work in the field and computer modelling. Recent results from the rangeland modelling project have indicated the important influence of goats on the stability and sustainability of rangeland systems. Consequently rangeland models depend on accurate representation of the performance of goats and their impact on the vegetation and on the productivity of the whole system. The end products of microbial fermentation in the rumen provide the major proportion of nutrients available to the host animal.
Many microbial species are present in the rumen and most are selective fermenters.
The pattern of end products produced and rate of fermentation varies with the relative proportions of species present and the food eaten. The rumen microbial population varies with the diet, amount eaten and time since a specific food was eaten. The different organisms interact with one another and with the rumen contents. Rumen models that simulate changes in the proportions of different microbial species are very complex even if only three types of organism are represented. To date no model incorporates rumen anaerobic fungi which may play important roles in the digestion of lignified rangeland plants.