• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.901-916
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• 2017

This study was conducted to evaluate natural plant extracts for methane gas reduction in ruminants. Rumen fluid was collected from cannulated Hanwoo cow ($450{\pm}30kg$) consuming 400 g/kg concentrate and 600 g/kg timothy. The 15 ml of mixture comparing McDougall's buffer and rumen fluid in the ratio 2 to 1, was dispensed anaerobically into 50 ml serum bottles. Rumen fluid contents were collected and in vitro fermentation prepared control (timothy, 300 mg), ginseng, balloon flower, yucca plant, camellia, tea plant and ogapi extracts were added at the level of 5% against 300 mg of timothy as a substrate (v/w) and incubated for 3, 6, 9, 12, 24, 48, and 72 h. In vitro pH values range 6.55~7.41, this range include rumen titration. The dry matter digestibility was not differ between all treatments and control. Total gas emission was significantly higher (p<0.05) in ginseng and balloon flower treatments on 24 h than in control. Carbon dioxide emission was not differ all treatments on 9 h than in control and significantly higher (p<0.05) yucca plant, camellia and tea plant treatments on 12 h than control. Methane emission was not differ all treatments on 6 h than in control. The rumen microbial growth rate was significantly higher (p<0.05) in ginseng, balloon flower on 12 h and significantly higher (p<0.05) in ginseng, yucca plant, tea plant and ogapi treatments on 24 h than in control. Total VFA was significantly higher (p<0.05) in tea plant and ogapi treatments on 12 h than in control and significantly higher (p<0.05) in ginseng, balloon flower treatments on 48 h than in control. Acetic acid was significantly lower (p<0.05) in ginseng and balloon flower treatments on 24 h than in control. Propionic acid was significantly higher (p<0.05) in ginseng and balloon flower treatments on 48 h than in control. As a results, sixth natural plant extracts had no significant effect dry matter digestibility and negative on rumen fermentation, but not effect methane reduction.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.696-704
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• 2015

This study was carried out to evaluate the optimum operational condition of Semi-continuously Fed and Mixed Reactor (SCFMR) to treat the dairy cow manure and saw dust mixture. Step-wise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) were utilized until the biogas volume became significantly decreased at mesophilic temperature ($35^{\circ}C$). The optimum operating condition of the SCFMR fed with TS 13% dairy cow manure and saw dust mixture was found to be an HRTs of 25 days and its corresponding OLRs of $4.45kg\;VS/m^3-day$. At this condition the biogas and methane production rates were 1.44 v/v-d and 1.12 v/v-d (volume of biogas per volume of reactor per day), respectively and the TVS removal efficiency of 37% was achieved. The successful operation with such a high OLR was due to the high reactor alkalinity concentration of 14,500~15,600 mg/L as $CaCO_3$ as a result of the characteristic of the original substrate, dairy cow manure and saw dust mixture whose alkalinity was more than 8,000 mg/L as $CaCO_3$. The parameters for the reactor stability, the ratios of volatile acids and alkalinity concentrations (V/A) and the ratio of propionic acid and acetic acid concentrations (P/A) appeared to be 0.11 and 0.43, respectively, that were greatly stable in operation. Free ammonia toxicity was not experienced due to the long term acclimation by the reactor TS content ranged 7.2~10.4% during the entire operational period.