The morphometric variations of the rumen papillae due to different alimentary diets has been analysed using a geographic information system (GIS), as the preliminary stage of a wider study aimed at creating a geo-database to link environmental data (pasture structure and composition, pastoral value) with parameters measuring animal welfare (body condition score, volatile fatty acids concentration, haematochemical profile) both during a pasture vegetative cycle and in different conditions of animal load on pastures, with the ultimate goal of contributing to grassland management. A first step was to collect samples of rumen wall tissue from different groups of sheep (lambs to milky and mixed diet, and adult at the maximum of flowering and at the end of pasture vegetative cycle) to verify morphometric differences in rumen papillae due to different diets. Wall tissues of rumen samples were removed from the dorsal and ventral sac and preserved in a formalin solution. Twenty papillae from the dorsal and ventral sac were taken from each sample and their images were elaborated with ArcGISTM software. Results show that the morphometric variation of papillae is related with the pasture productivity trend: the maximum size of rumen papillae occurs immediately after the phytomass and flowering spike; in this phase the animals utilise a very nourishing and quantitatively abundant pasture. After this phase, a deterioration of pasture occurs and the surface of rumen papillae surface decreases rapidly. Results obtained further confirm the existence of a close relationship between quality and quantity of phytomass and the extent of rumen papillae absorptive surface, demonstrating the effects of this relationship during a pasture vegetative cycle.