The influence of the host on the population profile and on the ciliate populations of the bovine rumen was investigated using three suckling crossbred friesian-zebu (Gir) cows, with fistulas. The genera of ciliate observed in the three hosts examined have characterized the populations as type A. The occurrence of the genera of ciliate was related to the host. lt was verified that the rumen ciliate were quantitatively influenced by inherent factors in the host animais, showing a significam difference in the total of ciliate among the hosts in ali stages of the experiment.-