EFFECT OF KINDS OF HAY ON POPULATION-DENSITIES OF RUMEN ANAEROBIC FUNGI

To clarify the relationship between population densities of rumen anae robic fungi and the chemical composition of grass and legume hays, rum en fermentation and retention time of particles in the rumen, male Cor riedale sheep (3) were given either oats hay, timothy hay or lucerne h ay chopped to 2 cm @ 2.5 % of live weight in the Latin square design. The passage rats of particulate and liquid fractions, volatile fatty a cids and population densities of rumen fungi were characterised. Popul ation densities of rumen fungi were determined by roll-tribe method an d agar-strip method. Population densities of ruminal fungi did nor cor relate with the chemical composition of oats, timothy and lucerne hays nor with rumen fermentation in the present study. Results of fraction al outflow rate or mean retention time of digesta particles suggested that a slower outflow rate or a longer mean retention time of particle s offers a higher possibility of fungal growth on digesta particles gr eater than 0.30 mm in the rumen.