The major aim of this study was to evaluate the effect of fat content of sunflower meal (150 and 30 g fat /kg dry matter, high and low fat, respectively) on population, growth and activity of rumen anaerobic fungi by using direct (quantitative competitive polymerase chain reaction, QC-PCR) and indirect (dry matter (DM) and neutral detergent fibre (NDF) disappearance in rumen fungi media culture for 12 days) methods. The results of QC-PCR showed that rumen anaerobic fungi population in the medium containing high fat sunflower meal was greater as compared to low fat sunflower meal (+0.14 vs. +0.10) (P<0.05). Also, disappearance of dry matter after 12 days incubation with rumen fungi will be 36.1 and 35.7 g/100 g DM for high and low fat sunflower meal, respectively) (P>0.05). High fat of sunflower meal caused increase in natural detergent fibre disappearance 12 days after culturing as compared to low fat sunflower meal (145.2 vs 139.2 mg/g dry matter, respectively) (P<0.05). Therefore, it appears that fat content of sunflower meal does not negatively affect the population, growth and activity of rumen fungi.

Keywords