COMPARISON OF ANAEROBIC FUNGI IN FECES AND RUMEN DIGESTA OF NEWLY BORN AND ADULT RUMINANTS

Anaerobic fungi were first detected in faeces produced by newborn calv es and lambs at 4 and 5 wk after birth, respectively. populations deve loped gradually thereafter, until eventually the faeces produced by al l young ruminants contained anaerobic fungi. Anaerobic fungi were dete cted in the rumen of carves prior to their detection in faeces. Rumen digesta and faeces of adult Friesian dairy cows contained larger popul ations of anaerobic fungi than those detected in young ruminants. Intr oduction of wheat shaw particles, in small polyester bags, into the du odenum of fistulated adult cattle and retrieval of these bags from voi ded faeces established that the hindgut contained an active population of anaerobic fungi. In faeces, anaerobic fungi were similar to the mo nocentric and polycentric fungi commonly found in the rumen. The abili ty of faecal isolates to degrade plant cell-wall polymers was comparab le to that of the rumen fungus, Neocallimastix hurleyensis. However, w hereas fungal populations in faeces were able to withstand drying in a ir at ambient temperature, those present in rumen digesta failed to su rvive the drying process. These differences in the behaviour of anaero bic fungi in rumen digesta and faeces suggest that the faecal fungi ar e able to persist and survive due to the formation of cysts or resista nt zoosporangia.