This study aimed to investigate the effects of various washing pre-treatments of native Codium fragile as a feed additive on in vitro ruminal fermentation and CH4 production in ruminants. Seaweed was included at 0.5% dry matter (DM) based on the experimental feed (forage : concentrate = 3:7). Treatment groups were classified as follows: experimental feed (C), no washing (T1), washing at 0°C (T2), washing at 22°C (T3) and washing at 70°C (T4) each immersed for 6 minutes in distilled water. The pH consistently fell within the ruminal stability range. In vitro dry matter digestibility was significantly highest in T2, T3, T4 and C, T4 was the lowest at 48 h (p<0.05). NH3-N concentration was significantly highest in T4 at 48 h (p<0.05). Total gas production at 48 h was 19% lower in T4 compared to C (p<0.01). CH4 production (mL/g DM) at 48 h was lower in all treatment groups compared to C, with T3 showing a 31% reduction (p<0.01). Similarly, CH4 production (mL/g dry matter degradability, DMD) at 48 h was 39% lower for T3 compared to C (p<0.01). At 24 h, total VFA was significantly highest in T1 and T4 (p<0.05). The proportions of acetate was significantly highest in C and T3 was the lowest at 48 h (p<0.01). The proportions of propionate was significantly highest in T3 and C was the lowest at 48 h (p<0.01). The acetate to propionate ratio was singnificantly highest in C at 48 h (p<0.01). The proportions of butyrate at 24 h was lower for T3 compared to C (p<0.05). Therefore, this study confirms that Codium fragile can reduce CH4 production when used as a feed additive for ruminants and this effect is not significantly influenced by the washing pre-treatment. However, if washing process is necessary, washing at 22°C is the most appropriate method to remove foreign objects.

ABSTRACT1)
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 한우 반추위 내용물 채취
    2. 공시재료 및 in vitro 반추위 배양 실험
    3. 조사 항목 및 분석 방법
    4. 통계처리
Ⅲ. 결과 및 고찰
Ⅳ. 요약
사사
Ⅴ. 참고문헌

• 이혜안(한경대학교 동물생명융합학부 대학원생) | Hye An Lee (Graduate student School of Animal Life Convergence Science, Hankyong National University, Anseong 17579, Korea)
• 배귀석(한경대학교 바이오가스연구센터 전임연구교수) | Gui Seck Bae (Researcher professor, Biogas Research Center, Hankyong National University, Anseong 17579, Korea)
• 김상윤(한경대학교 동물생명융합학부 대학원생) | Sang Yoon Kim (Graduate student School of Animal Life Convergence Science, Hankyong National University, Anseong 17579, Korea)
• Narantuya Batburged(한경대학교 동물생명융합학부 대학원생)
• 정수연(한경대학교 동물생명융합학부 대학원생) | Soo Yeon Jung (Graduate student School of Animal Life Convergence Science, Hankyong National University, Anseong 17579, Korea)
• 최다현(한경대학교 동물생명융합학부 대학원생) | Da Hyun Choi (Graduate student School of Animal Life Convergence Science, Hankyong National University, Anseong 17579, Korea)
• 송기협(한경대학교 동물생명융합학부 학부생) | Ki Hyeop Song (Undergraduate student School of Animal Life Convergence Science, Hankyong National University, Anseong 17579, Korea)
• 김창현(한경대학교 동물생명융합학부 교수) | Chang Hyun Kim (Professor School of Animal Life Convergence Science, Hankyong National University, Anseong 17579, Korea) Corresponding author