Parameter of ruminal feed fermentation in vitro with addition of clove essential oil (Syzygium aromaticum L.) as feed additive

Abstract

Clove essential oils (CEO) effect as rumen modifier on rumen fermentation was studied using in vitro gas production technique. Feed consisted of king grass, wheat pollard and rice bran (60:20:20) were incubated in buffered rumen liquid at 39ºC for 24 hours with Ongole grade cattle rumen liquor as microbe donor. The CEO was added and mixed with feed to meet its levels of 0, 25, 50, 75, and 100 µl/L of fermentation medium. Volume of gas production was measured at the end of fermentation. Broth was collected for pH, protozoa number, ammonia, and microbial protein synthesis measurement. Medium pH ranges from 7.12 to 7.20, were not affected by CEO. Gas production reduced at CEO doses 75 and 100 µl/L (P<0.01). Ammonia concentration at all treatment was higher than control, whereas protozoa number were decreased by CEO (P<0.01). Protozoa ranged from 18.08 to 32.81 x 104 cell/ml reduced gradually by CEO doses 25 to 100 µl/L. Meanwhile, protein microbe at CEO 25 and 50 µl/L (141.54 and 141.11 mg/100 mL) were higher than control (P<0.01). CEO doses 75 and 100 µl/L did not change microbial protein. In conclusion, CEO addition up to 50 mg/l increase rumen feed efficiency.