This study was conducted to evaluate natural plant extracts for methane gas reduction in ruminants. Rumen fluid was collected from cannulated Hanwoo cow (450±30 kg) 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.

Ⅰ. 서 론
 Ⅱ. 재료 및 방법
  1. 공시동물 및 시험설계
  2. 공시재료 및 시험방법
  3. 조사항목
  4. 통계처리
 Ⅲ. 결과 및 고찰
  1. pH
  2. 건물 소화율
  3. 총 가스, 이산화탄소 및 메탄 발생량
  4. 미생물 성장량
  5. VFA(Volatile Fatty Acid)
 Ⅳ. 요 약
 References

• 이신자(경상대학교 농업생명과학연구원&중점연구소) | Lee, Shin-Ja
• 엄준식(경상대학교 응용생명과학부(BK21)) | Eom, Jun-Sik
• 이수경(경상대학교 농업생명과학연구원) | Lee, Su-Kyoung
• 이일동(경상대학교 응용생명과학부(BK21)) | Lee, Il-Dong
• 김현상(경상대학교 응용생명과학부(BK21)) | Kim, Hyun-Sang
• 강한별(경상대학교 응용생명과학부(BK21)) | Kang, Han-Beyol
• 이성실(경상대학교 응용생명과학부(BK21)&농업생명과학연구원) | Lee, Sung-Sill Corresponding author