There is limited information on the impact that anthelmintic treatments exert on the fecal microbiome of growing cattle. This study characterizes the composition and metabolic function of the cattle gut microbiome associated with different levels of parasite Fecal Egg Counts (FEC) and characterizes the fecal microbiome before and after ricobendazole-treatment. The hypothesis was that FEC levels and ricobendazole treatment (8 mL/animal RICOVERM 15 g) alter the fecal microbiome structure and predicted functionality. Fecal samples from Angus yearling steers (live weight:249±19 kg) with Low-FEC (