Eating and ruminating behavior, as well as salivary secretion, are important factors in intake regulation and digestion in ruminants. This research presents several objectives : 1. the study of nycterohemeral rhythm of parotid and mandibular salivary secretion (flows and composition), 2. quantitative analysis of eating and ruminating behavior and its factors of variation (food, species, genotype), 3. description of ruminal fauna and its evolution according to different factors of variation, 4. measurement of digestion kinetics of various feeds.