dc.description.abstract | Supplementation of vegetable oils containing high unsaturated fatty acids is a common practice in ruminant feed to increase the quality of meat. The objective of this research was to assess the effect of canola and flaxseed oils protected with Ca soap in rumen during fermentation in vitro at 4 and 8 hours. The design used in this experiment was a rendomized complete block design with 3 treatments and 4 replications. The treatments consisted of forage and concentrate with ratio 60 : 40 (control), control + Ca soap canola oil 6% and control + Ca soap flaxseed oil 6%.Variables observed in this research were population of rumen microbes (total bacteria and protozoa population), total VFA, molar proportion, estimation of methane production, and fatty acid profile at 4 and 8 hours incubation. The results showed that the treatments did not affect the population of rumen microbes. The use of Ca soap flaxseed oil increased total VFA, proportion of propionate and methane production estimation. At the 4 hour incubation, Ca soap canola oil suffered considerable biohydrogenation 79.35%, while Ca soap flaxseed oil (49.36%). At the 8 hour fermentation, Ca soap falxseed oil suffered considerable biohydrogenation at 66.24%, while Ca soap canola oil at 81.41%. | id |