Study On Effects Of Essential Oils And Its Active Compounds On Rumen Fermentation In Dairy Cow

This paper included three experiment,; The first trial was studied on effect of different doses of thymol (0,4.5,45,450mg/L)and oregano oils(0,45,450,4500mg/L)) on rumen fermentation and methane eminssion of dairy cows in vitro 24-h batch culture of rumen fluid with a 60:40 forage:concentrate diet , the aim was to select suitable oregano oils and thymol range of supplement; In the second experiment, 12 dual-flow continuous culture fermenters (1000 mL) were used in 4 replicated periods (3 d of adaptation and 3 d of sampling) to study the effects of THY and OREG on rumen microbial fermentation,The culture were two types of liquid dilution rate with LDR (11.84%/h,17.76%/h) , Fermenters were fed 20g/d of DM of a 60:40 forage:concentrate diet, The results were as follows:(1) The results of batch culture showed that the effects of thymol and oregano oils on rumen fermentation were different under diets with forage to concentrate ratio of 4:6. Thymol than oregano oil on rumen fermentation and reduce methane production more strongly.According to MFAEI, optimal supplemental doses of thymol and oregano oils were 4.5mg/L and 45mg/L respectively.(2) The results of continuous culture showed that the effects of thymol and oregano oils on rumen fermentation were different under dilution rate with LDR (11.84%/h,17.76%/h) , incubated liquid pH, concentration of MCP, acetate, butyrate and TVFA, with the LDR increases the rise, incubated liquid concentration of NH3-N, propionate, with the LDR increases the reduce. According to MFAEI, optimal supplemental range of thymol and oregano oils were 4.5mg/L～45mg/L and 45mg/L～450mg/L respectively.(3)Batch culture and continuous culture compared;batch culture in the orgeno oil and thymol the maximum dose (T450 and N4500) significantly increased the concentration of acetate, and acetate: propionate,lower the concentration of propionate ,thymol the maximum dose (T450) significantly reduced the concentration of TVFA; orgeno oil the maximum dose (N4500) reduced the concentration of TVFA; but there was no significant difference (P﹥0.05). continuous culture in the orgeno oil and thymol the maximum dose (T450andN4500) significantly reduced the concentration of acetate, TVFA; and acetate: propionate,increased the concentration of propionate , Thymol and oregano oil have increased the concentration of butyrate in the two culture systems, However, a significant increase in the degree of difference,Two types of culture system in the outcome of inconsistent.