본 시험은 항염에 효과가 있다고 알려진 식물 추출물의 첨가가 반추위 발효와 메탄 생성에 미치는 영 향을 알아보기 위해 in vitro 실험을 수행하였다. 항염과 항산화 효과가 있는 산뽕나무, 뽕나무, 예덕나 무, 오동나무, 방아풀과 은행나무 6종을 선발하였다. 반추위액과 McDougall buffer 혼합액 15mL과 티 모시 0.3g, 각각의 추출물을 기질의 5%로 넣고 39℃에서 3, 9, 12, 24, 48 그리고 72시간 배양하였다. 항염 효과가 있는 식물 추출물의 첨가는 반추위 발효 성상(pH, 건물소화율, Glucose 농도, 암모니아 농도, 단백질 농도, 미생물 성장량, 휘발성지방산)에는 영향을 미치지 않았다. 총 가스 발생량은 각기 다른 양상을 보였으며, 이산화탄소 발생량은 48시간대에서 예덕나무와 방아풀에서 대조구에 비해 유의 적(p<0.05)으로 높았다. 또한 메탄 발생량은 배양 초기에는 대조구보다 첨가구에서 유의적(p<0.05)으로 감소하였으나, 발효가 진행될수록 대조구에 비해 첨가구에서 더 많은 메탄이 발생하였다. Polyphenol과 flavonoid는 은행나무 추출물구에서 가장 높았다. 본 시험의 결과에서 항염에 효과가 있는 식물 추출물 을 in vitro 반추위 배양액에 첨가하였을 때, 반추위 발효에는 영향을 미치지 않았고, 메탄은 초기 발효 에 저감 효과가 있는 것으로 사료된다.

In order to reduce odor and methane emission from the landfill, open biocovers and a closed biofilter were applied to the landfill site. Three biocovers and the biofilter are suitable for relatively small-sized landfills with facilities that cannot resource methane into recovery due to small volumes of methane emission. Biocover-1 consists only of the soil of the landfill site while biocover-2 is mixed with the earthworm casts and artificial soil (perlite). The biofilter formed a bio-layer by adding mixed food waste compost as packing material of biocover-2. The removal efficiency decreased over time on biocover-1. However, biocover-2 and the biofilter showed stable odor removal efficiency. The rates of methane removal efficiency were in order of biofilter (94.9%)>, biocover-1(42.3%)>, and biocover-2 (37.0%). The methane removal efficiency over time in biocover-1 was gradually decreased. However, drastic efficiency decline was observed in biocover-2 due to the hardening process. As a result of overturning the surface soil where the hardening process was observed, methane removal efficiency increased again. The biofilter showed stable methane removal efficiency without degradation. The estimate methane oxidation rate in biocover- 1 was an average of 10.4%. Biocover-2 showed an efficiency of 46.3% after 25 days of forming biocover. However, due to hardening process efficiency dropped to 4.6%. After overturn of the surface soil, the rate subsequently increased to 17.9%, with an evaluated average of 12.5%.

본 연구는 약용실물 수피 추출물을 이용하여 in vitro 반추위 발효성상 및 반추위 메탄 발생에 미치 는 영향을 알아보기 위해 수행되었다. 공시재료는 무궁화, 음나무, 팽나무, 두충 및 후박나무 추출물을 사용하였다. McDougall’s buffer와 반추위액을 2:1 비율로 혼합한 발효액을 티모시 0.3g과 식물 추출 물이 담긴 50mL serum bottle에 혐기상태로 20mL 분주한 뒤, 39℃에서 3, 6, 9, 12, 24, 48 및 72시 간 동안 발효하였다. 약용식물 수피 추출물을 첨가하였을 때 반추위 발효 성상(pH, 건물소화율, 암모니 아태 질소, 미생물 성장량)에는 영향을 미치지 않았다. 배양 6시간대에 두충 추출물 첨가구에서 acetate의 농도가 대조구에 비해 유의적(p<0.05)으로 낮고, 메탄의 기질인 이산화탄소의 발생량이 대조 구에 비해 유의적(p<0.05)으로 낮아 메탄 저감 효과를 기대하였으나 메탄 저감효과는 없었다. 메탄생성 박테리아인 Methanogen archaea의 경우 무궁화 추출물 첨가구를 제외한 전 추출물 첨가구에서 대조구 에 비해 유의적(p<0.05)으로 높았으나 메탄발생량에는 유의적(p<0.05)인 차이가 없었다. 추후 첨가 농 도를 달리하거나 flavonoid 함량을 측정하는 실험이 필요한 것으로 사료되며, 메탄생성박테리아를 감소 시키는 연구도 추가적으로 필요할 것으로 생각된다

This study was conducted to investigate the effects of antiprotozoal plant extracts on in vitro ruminal fermentation and methane emission. Ruminal contents were collected from two ruminally-fistulated steers (Average BW: 450±30 kg) consuming 60% Timothy hay and 40% concentrate with free access to water and mineral block. Plant extracts, Lonicera japonica, Torreya nucifera, Zanthoxylum schinifolium, Poncirus trifoliate and Citrus junos, which have been known to have antiprotozoal and antiparasitic effects were added (5% of substrate) to the in vitro ruminal fermentation bottles containing the mixture of rumen fluid and McDougall’s buffer. The McDougall buffer (1000 ml) and ruminal inoculums (500 ml) were combined and 20 ml added to the 50 ml fermentation vessels containing 300 mg of substrate (DM basis). The fermentation vessels were placed in an incubator at 39°C for 3, 6, 9, 12, 24, 48 and 72 h with shaking. Plant extracts addition was decreased (p<0.05) acetate:propionate compared with control except with T. nucifera addition. Total gas production was increased (p<0.05), whereas methane emission was decreased (p<0.05) by all plant extracts compared with control at 12 h incubation. Methane emission at 24 h incubation was decreased for Lonicera japonica, Torreya nucifera, and Zanthoxylum schinifolium compared with control as well. In addition, methanogenic archaea was decreased (p<0.05) by all plant extracts at the 12 h incubation. These results indicate that the plant extracts may decrease methane emission by inhibiting methanogenesis without the decrease of total gas production in 12 h in vitro ruminal fermentation. Therefore, plant extracts which have the antiprotozoal effect may be promising feed additives for ruminants as a methane inhibitor

The objective of this study was to determine how feeding forage and concentrate separately (SF) or as a total mixed ration (TMR) affects enteric methane production of cattle. Six Holstein steers (203 ± 22.5 kg) were used in a 2 × 3 changeover design experiment. Experimental diets (TMR and SF) consisted of compound feed, timothy hay and soybean curd residue in a ratio of 40:48:12, respectively, and diets were fed at 10% of metabolic body weight, on an as-fed basis. There were no differences in dry matter intake and enteric methane production (g/d) between SF and TMR but the methane conversion rate (methane energy/GE intake) of TMR was significantly higher (p=0.05) than that of SF. The mean methane emission factor (kg/head/year) and conversion rate of the two treatments were 21.4 and 0.05, respectively. There was a strong relationship between metabolic body weight and enteric methane production (p<0.001). At the present time, further studies may be necessary in order to establish the effects of TMR and SF on enteric methane production.

This study was conducted to evaluate effects of supplementation of Bifidobacterium ruminantium on in vitro ruminal fermentation and methane production. Ruminal fermentation characteristics of Timothy hay (C1), whole barley (C2), Timothy hay + B. ruminantium (T1) and whole barley + B. ruminantium (T2) were evaluated at 0, 3, 6, 9, 12, 24 and 48 h incubation at 39℃. The amount of B. ruminantium culture added into T1 and T2 was 0.3 ml. The pH values ranged from 5.99 to 6.83 in all the treatments. Concentration of NH3-N of C2 and T2 was higher than C1 and T1 at 48 h (p<0.05). The total gas production of C2 and T2 was higher than C1 and T1 at 9 h (p<0.05). The total methane production of treatments with B. ruminantium was not significantly different at 24 and 48 h (p<0.05). Concentration of lactic acid was significantly different between both substrates (p<0.05). Therefore, B. ruminantium supplementation was determined to be insignificant in the in vitro ruminal fermentation and methane production, while a further study was required to investigate relation to lactic acid production with different forage sources.

본 시험은 질산염함유 식물 추출물을 이용하여 in vitro 반추위 발효성상 및 반추위 메탄 발생에 미 치는 영향을 알아보기 위해 수행되었다. 공시재료는 감자, 당근, 배추, 상추 및 시금치 추출물을 사용하 였으며, 발효 기질은 2mm로 분쇄된 timothy 0.3g을 사용하였다. In vitro 실험은 조사료(timothy) 및 배합사료를 6:4의 비율로 급여한 반추위 cannnula가 시술된 한우 암소에서 채취하였다. 반추위액과 McDougall’s buffer를 1:2의 비율로 혼합한 발효액을 0.3g timothy와 식물 추출물이 담긴 50mL serum bottle에 혐기상태로 20mL 분주한 뒤, 39℃에서 9, 12, 24, 48시간 동안 발효하였다. pH는 발 효 시간이 증가함에 따라 점점 감소하며, 6.31~6.96으로 정상범위였다. 건물 소화율은 9시간 배추 추 출물구에서 유의적으로 낮았고, 암모니아 농도는 감자, 배추, 상추 추출물구에서 대조구에 비해 첨가구 에서 유의적으로(p<0.05) 낮았으며, 반추위 미생물 성장량은 발효 24시간대의 당근 추출물구에서 높았 다(p<0.05). Acetate와 propionate 농도는 대조구에 비해 첨가구에서 유의적으로 낮았으며(p<0.05) butyrate 농도는 첨가구간에 발효시간별로 각각 다른 양상을 보였다. 총 가스 발생량은 발효 12시간 및 24시간대에서 배추, 상추, 시금치 추출물구에서 유의적으로(p<0.05) 낮았으며, 메탄 발생량은 감자, 배 추, 시금치 추출물구가 대조구에 비해 유의적으로(p<0.05) 낮았고, 이산화탄소 발생량 또한 첨가구에 비해 대조구에서 유의적으로(p<0.05) 낮았다. 결과적으로 본 시험에 사용된 5종의 질산염 함유 식물 추 출물은 반추위 발효에 악영향을 미치지 않으면서 메탄저감 효과를 나타내었다. 특히 배추 추출물은 반 추위내 메탄발생을 저감시킬 수 있는 식물추출물로서 가능성이 높은 것으로 사료된다.

Global warming is considered one of the great challenges of the twenty-first century. In order to reduce the ever-increasing amount of methane (CH4) released into the atmosphere, and thus its impact on global climate change, CH4 storage technologies are attracting significant research interest. CH4 storage processes are attracting technological interest, and methane is being applied as an alternative fuel for vehicles. CH4 storage involves many technologies, among which, adsorption processes such as processes using porous adsorbents are regarded as an important green and economic technology. It is very important to develop highly efficient adsorbents to realize techno-economic systems for CH4 adsorption and storage. In this review, we summarize the nanomaterials being used for CH4 adsorption, which are divided into non-carbonaceous (e.g., zeolites, metal-organic frameworks, and porous polymers) and carbonaceous materials (e.g., activated carbons, ordered porous carbons, and activated carbon fibers), with a focus on recent research.

The validity of landfill gas models is an important problem considering that they are frequently used for landfill-site-related policy making and energy recovery planning. In this study, the Monte Carlo method was applied to an landfill gas generation model in order to enhance conformity. Results show that the relative mean deviation between measured data and modeled results (MD) decreased from 19.8% to 11.7% after applying the uncertainty range of Intergovernmental Panel on Climate Change (IPCC) to the methane-generation potential and reaction constants. Additionally, when let reaction constant adjust derived errors from all other modeling components, such as model logic, gauging waste, and measured methane data, MD decreased to 6.6% and the disparity in total methane generation quantity to 2.1%.

The present in vitro study was conducted to examine the effect of buffer solubility of eight protein feeds (coconut meal, distillers grain, sesame meal, perilla meal, soy source cake, rape seed meal, soybean meal and lupine) on the fermentation characteristics, degradability of dry matter (DM) and crude protein (CP), and methane (CH4) production by rumen microbes. Buffer extraction increased pH (P<0.05 ~ p<0.001) of the culture solution but tended to lower ammonia- N concentration for all protein feeds. Total volatile fatty acids(VFAs) and each VFAs concentrations in all incubation was decreased by buffer extraction (P<0.01 ~ P<0.001). Also, molar proportion of acetate in 1h (P<0.001), 3h (P<0.01) and 12h (P<0.05) incubations and molar proportion of propionate in 1h (P<0.001), 3h (P<0.01), 6h (P<0.05) and 12h (P<0.05) were decreased by buffer extraction. But molar proportion of butyrate in 1h (P<0.001), 3h (P<0.01) and 6h (P<0.05) were increased by buffer extraction. The in vitro effective degradability of dry matter (P<0.001) and CP (P<0.001) was decreased by buffer extraction. The methane production (P<0.01~P<0.001) in all incubation was decreased by buffer extraction. The results from in the current study might be useful for diet formulation to improve the feed efficiency of the ruminant animals without massive loss of major nutrients.

본 연구는 탄닌 함유 식물 추출물을 이용하여 in vitro 반추위 발효성상, 미생물 성장 및 메탄생성에 미치는 영향을 알아보고자 수행하였다. 반추위액은 농후사료와 조사료(timothy)를 40:60의 비율로 급 여한 반추위 cannula가 시술된 한우 암소에서 채취하였다. 본 실험에 사용한 식물 추출물은 상수리나 무(Quercus acutissima), 밤나무(Castanea crenata), 참가시나무(Quercus salicina), 졸참나무 (Quercus serrata) 그리고 떡갈나무(Quercus dentata)를 사용하였으며, 식물 추출물은 한국식물추출물 은행에서 분양받아 사용하였다. 반추위액과 McDougall buffer를 1:2의 비율로 혼합한 배양액을 0.3g timothy와 식물 추출물(기질의 5%)이 담긴 50mL serum bottle에 혐기상태로 15mL를 분주하였다. Serum bottle은 39℃, 120rpm으로 3, 6, 9, 12, 24, 48 및 72시간 동안 배양하였다. 본 실험 결과 배 양 시간이 지날수록 pH는 점점 감소하였으며, 정상범위에 포함되었다. 건물소화율은 대조구에 비해 첨 가구에서 유의적(p<0.05)으로 낮았다. 암모니아, 총 가스 생산량 및 이산화탄소 발생량은 대조구에 비 해 첨가구에서 유의적(p<0.05)으로 차이가 없었으나, 24시간 메탄 발생량은 대조구에 비해 전 첨가구에 서 유의적(p<0.05)으로 낮았다. 미생물 성장량은 첨가구에 따라 각각 다른 양상을 나타내었고, acetic acid 및 propionic acid는 대조구에 비해 첨가구에서 유의적(p<0.05)으로 낮았다. Real-Time PCR에서 섬유소 박테리아(R. albus, R. flavefaciens) 및 메탄 생성균(Ciliate associated methanogen)은 대조 군에 비해 유의적(p<0.05)으로 감소하였다. 결과적으로 본 실험에 사용한 탄닌 함유 식물 추출물 5종 모두 반추위 발효에 영향을 미치지 않으며, 메탄저감 효과를 나타내었다. 특히 상수리나무에서 반추위 발효성상에 악영향을 미치지 않으며 메탄 발생을 저감하는 식물 추출물로 적합하다고 생각된다.

본 연구는 long-chain fatty acids 첨가 시 발효 48 h 에 in vitro 반추위 발효와 메탄 생성에 미치는 영향을 구명하고자 수행하였다. 반추위액은 외과적 방법으로 누관이 장착된 홀스타인에서 채취하였으며, 공시축의 사양관리는 조사료와 농후사료 6:4 비율로 하였다. 60 mL serum bottle 에 buffer 10 mL, 티모시 0.3 g, 위액 5 mL 를 각각 넣고 fatty acids(stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid ; 0.001%/15 mL)를 첨가한 뒤 발효시간대별(3, 6, 12, 24, 36 및 48 h)로 5 처리 3 반복 수행하였다. 발효종료시간인 48 h 에서 pH 는 oleic acid 와 linoleic acid 는 대조구에 비해 유의적(p<0.05)으로 높게 측정되었다. 48 h 에 총가스 발생량은 stearic acid 가 유의적(p<0.05)으로 높게 측정되었고 메탄 발생량은 arachidonic acid 에서 유의적(p<0.05)으로 높게 측정되었다. 건물 소화율은 발효 36 h 에서 linoleic acid 가 다른 처리구에 비해 높았으나, 발효 48 h 에서는 처리구간 유의차가 없었다. 휘발성 지방산 농도와 butyric acid 는 발효 3 h, 12 h 에서 long-chain fatty acid 처리구가 대조구에 비해서 유의적(p<0.05)으로 높게 나타났다. 3 h, 12 h 에서 acetic acid는 linoleic acid, linolenic acid 가 다른 처리구보다 유의적(p<0.05)으로 높게 나타났고, propionic acid 는 stearic acid, oleic acid 에서 다른 처리구에 비해 유의적(p<0.05)으로 높게 측정되었다. Protozoa 의 생존 수와 사멸 수는 처리구간의 차이를 나타내지 않았다. Bacteria 는 linolenic acid 와 arachidonic acid 가 다른 처리구에 비해 유의적(p<0.05)으로 높았다. Fungi 는 oleic acid 가 linoleic acid 를 제외한 나머지 처리구에서 유의적(p<0.05)으로 높게 측정되었다. 본 연구의 결과에 의해 발효 48 h 에 0.001%의 oleic acid 와 linoleic acid 의 첨가는 메탄 발생량을 감소시키는데 효과적이라는 것을 알 수 있었다.

구름버섯(Trametes versicolor)은 phenolic compound인 CV와 MG를 효과적으로 탈색할 수 있었으며 고체와 액체배양 상태 모두에서 CV보다 MG를 더 효과적으로 탈색시켰다. 구름버섯에 의한 두 색소의 탈색 과정에서 phenolic compounds를 분해하는 것으로 알려진 세 가지 효소 중 laccase의 활성이 가장 높았다. MnP 역시 적은 수치지만 활성을 나타냈으며 LiP의 활성은 나타나지 않았다. 따라서 구름버섯에 의한 합성염료의 분해과정에서 laccase가 주로 사용되고 MnP는 탈색과정에서 보조적인 작용을 하는 것으로 추정된다. 그러나 CV의 경우 MnP가 활발하게 염료분해에 관여하는 것으로 판단된다. 또한 MG가 대부분 탈색되었을 때의 laccase 활성(0.16 U/mg)이 CV가 대부분 탈색되었을 때의 활성(0.23 U/mg)보다 현저하게 낮은 것으로 보아 구름버섯이 CV를 탈색시키는데 더 높은 활성의 laccase가 필요로 하는 것이 밝혀졌다. 본 실험에서 한국산 구름버섯 종의 CV와 MG 탈색능력이 확인되었으며 앞으로 한국산 구름버섯을 이용한 triphenyl methane계에 속하는 합성염료의 분해에 관한 친환경적 처리기술 개발에 도움이 될 것으로 기대된다.

Landfills are nettlesome sources of malodorous gases as well as methane that has the second largest radiative forcing of long residence-greenhouse gases, followed carbon dioxide. Because methane and malodorous gases are simultaneously emitted in landfills, investigation of whether or not methane and malodorous gases affect each other’s degradation is important. Amines such as monomethylamine(MMA), dimethylamine(DMA) and trimethylamine(TMA) are representative malodorous gases from landfills. In this study, the effect of amines on the bio-oxidation of methane was evaluated using a methane-oxidizing consortium where the dominant bacteria were Methylocystis spp. Amines inhibited the methane oxidation by the consortium, and the inhibition effect increased in the order of TMA > DMA > MMA. Methane oxidation rates in the consortium decreased with increasing amine/methane ratio(mol/mol). These results can be used to design and optimize the biological processes for simultaneous removal of methane and malodorous gases.

본 연구는 다양한 사료들을 유지수준에서 섭취한 한우 암소 경산우의 에너지 대사 시험의 결과로 부터 섭취에너지 균형과 메탄배출계수를 구하였다. 오차드그라스(orchard grass) 위주의 혼합목건초 섭취 7두, 혼합목건초의 30~50% 를 볏짚으로 대체한 12두, 혼합목건초와 볏짚에 밀기울 (wheat bran) 1 kg 추가급여한 6두, 총 25 개체의 대사실험 성적을 분석하였다. 실험축은 10일간 대사틀에서 개체별로 각각의 실험사료 적응 및 7일간 분 뇨 시료채취 후, indirect respiratory chamber 1대에 교대로 수용되어 1일간 호흡대사 실험이 이루어졌다. 혼합목건초 단독 급여구와 비교하여 나머지 두 처리구의 평균 건물섭취량은 약 11%, 15% 높았으나 통계적인 유의성은 없었고, gross energy (GE) 섭취량도 차이가 없었다. 총 섭취에너지 중 메탄으로 손실된 에너지 비율인 메탄전변율(methane conversion rate, Ym)과 메탄배출계수(emission factor, kg/head/year)도 각각 0.055~0.062 (평균 0.058)와 33.6~38.6(평균 35.2) 범위로 처리간 유의성이 없었다. 본 실험에서는 혼합목건초를 볏짚으로 대체하거나 또는 밀기울 추가급여에 의한 메탄발생량 차이가 없었으나, 메탄발생량을 줄일 수 있는 것으로 알려진 양질 조사료 급여효과 연구는 축산현장의 온실가스 감축 사업 참여가 가능한 분야이기 때문에 추가 연구들을 통해 시급히 증명되어져야 된다고 판단된다.

We developed a high-performance methane gas sensor based on a SnO2 hollow hemisphere array structure of nano-thickness. The sensor structures were fabricated by sputter deposition of Sn metal over an array of polystyrene spheres distributed on a planar substrate, followed by an oxidation process to oxidize the Sn to SnO2 while removing the polystyrene template cores. The surface morphology and structural properties were examined by scanning electron microscopy. An optimization of the structure for methane sensing was also carried out. The effects of oxidation temperature, film thickness, gold doping, and morphology were examined. An impressive response of ~220% was observed for a 200 ppm concentration of CH4 gas at an operating temperature of 400˚C for a sample fabricated by 30 sec sputtering of Sn, and oxidation at 800˚C for 2 hr in air. This high response was enabled by the open structure of the hemisphere array thin films.

This study was conducted to examine the effects of defaunation (removal of live protozoa) on fermentation characteristics, degradation of ryegrass hay and CH4 (methane) production by rumen microbes when incubated with plant oils (SO, sunflower oil and LO, linseed oil) in vitro. Sodium lauryl sulfate (0.000375 g/ml) as a defaunation reagent was added into the culture solution and incubated anaerobically up to 24 h at 39℃. pH from defaunation was increased for all treatments from 6 h incubation times (p<0.01-0.001) compared with those from fauantion. Concentration of ammonia-N from defaunation is higher than that from faunation at 3 h (p<0.001), 12 h (p<0.05) and 24 h (p<0.001) incubation times. Defaunation decreased (p<0.01-0.001) total volatile fatty acid concentration at all incubation times. Molar proportions of C2 (acetate, p<0.05-0.001) and butyrate (p<0.01-0.001) were also decreased by defaunation at all incubation times. Molar proportion of C3 (propionate), however, was increased by defaunation at all incubation times (p<0.001). Thus the rate of C2 to C3 was decreased by defaunation at all incubation times (p<0.001). Defaunation decreased ED (effective degradability) of dry matter (p<0.001) and ED of neutral detergent fiber (p<0.001) of ryegrass hay. Defaunation decreased total gas, CH4 production, CH4 % in total gas and CH4/CO2 at all incubation times (p<0.001). Oil supplementation decreased total gas (p<0.05-0.001), CH4 production (p<0.001) and CH4 % in total gas (p<0.001) compared with control at all incubation times. The result of this study showed that defaunation combined with oil supplementation may cause an alteration of microbial communities and further medicate the fermentation pattern, resulting in both reduction of degradation of ryegrass hay and CH4 production. No difference, however, was observed in all the examinations between SO and LO.

Methanol was directly produced by the partial oxidation of methane with four-component mixed oxide catalysts. Four-component(Mo-Bi-Cr-Si) mixed oxide catalysts were prepared by the co-precipitation and sol-gel methods. The catalyst prepared by the sol-gel method showed about eleven times higher surface area than that prepared by the co-precipitation method. From the O2-TPD experiment of the prepared catalysts, it was proven that there exists two types of oxygen species, and the oxygen species that participates in the partial oxidation reaction is the lattice oxygen desorbing around 750℃. The optimum reaction condition for methanol production was 420°C, 50 bar, flow rate of 115 mL/min, and CH4/O2 ratio of 10/1.5, providing methane conversion and methanol selectivity of 3.2 and 26.7%, respectively.

The objective of this study was to know the in vitro effects of supplemental anthelmintic plant extracts on the inhibition of protozoa for reducing methane production in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The plant extracts (Lonicera japonica, Zanthoxylum piperitum, Pyrethrum, Torreya nucifera, Ruta graveolens) known to have anthelmintic effect were added to the in vitro fermentation bottles containing the rumen fluid and medium. The rumen protozoal population was depressed by the addition of Pyrethrum, Torreya nucifera and Ruta graveolens. The methane production was also significantly (p<0.05)reduced by addition of Pyrethrum (2.20 ml/g DM), Torreya nucifera (2.36 ml/g DM) and Ruta graveolens (2.20 ml/g DM). The microbial growth in the treatments of Ruta graveolens or anthoxylum piperitum was the greatest after 12 h and 24 h incubations, respectively. The results of this study indicated that anthelmintic plant extracts appeared to reduce methane production by inhibition of ruminal protozoa related with the methanogens living endosymbiotic in protozoal cells.