CHARACTERIZING THE FORCES THAT SHAPE THE SUCESSION OF THE RUMEN MICROBIOME DURING THE FIRST DAYS OF LIFE

Ruminants are herbivorous which possess a great significance for mankind as a source for milk and meat. These mammals are fully dependent on their gut microorganisms in order to attain energy from plant fiber. In newborn calves, the rumen undergoes structural and physiological changes with age, which occur due to development of rumen microorganisms and their fermentation products. As for today, the establishment and colonization process of the microbial communities in the young rumen is not fully understood. For example, the present of several microbial taxa essential for adult rumen function such as fiber and starch degrading, were observed one day after birth although the calf hasn`t been exposed to this type of food yet. Furthermore, the effect of different factors such as the initial microbial composition and the diet on the development of the rumen microbiome remains to be elucidated. In the present work, rumen fluids from 1-7 days old newborn calves (n=12) were sampled, in-vitro, molecular and analytical techniques are used in order to better understand the acquisition process (stochastic vs. deterministic process) and the mechanism that govern the establishment of the microbial communities early in life.