CHANGES IN THE POPULATION OF SOME FUNCTIONAL GROUPS OF RUMEN BACTERIA INCLUDING METHANOGENIC BACTERIA BY CHANGING THE RUMEN CILIATES IN CALVES

Abstract

Twelve unfaunated male calves aged 5-8 months were inoculated with monogeneric protozoa (Epidinium ecaudatum, Eudiplodinium maggii or Entodinium. spp.) or mixed protozoa population. Thus, five groups of rumen protozoa population were established; Unf (unfaunated, protozoa- free), Epi (Epidinium ecaudatum mono-faunated), Eud (Eudiplodinium maggii mono-faunated), Ent (Entodinium spp. mono-faunated), and Mix (mixed Ophryoscolecids protozoa faunated). The number of total viable bacteria in the rumen was significantly lower in the Epi, Eud and Mix groups than the Unf group. The population of amylolytic bacteria was significantly lower in the Epi group than the Unf group. That of pectinolytic bacteria was higher in the Ent group than the other faunated groups. The number of methanogenic bacteria was significantly higher in the Ent, Eud and Mix groups than Unf, however the Epi group had a lower value than the other faunated groups. The concentration of rumen ammonia-N peaked at 1h after feeding and was significantly higher in the Mix group than in the other groups, and was the lowest in the Unf group. The concentration of rumen volatile fatty acids (VFAs) increased until 2h after feeding. The values of the Unf group were lower than the other groups, but the differences were not significant. The molar proportion of acetate was lowest in the Mix group, highest in the Unf group and the other groups had values intermediate between these two groups. The proportion of butyrate and propionate was lowest in the Unf group.