This study was to evaluate the feed value of whole crop rice silage (WCRS) and to investigate a suitable ratio of the WCRS and concentrate by an analysis of rumen fermentation. A total of 6 treatments were used according to WCRS: concentrate ratio on in vitro rumen fermentation: T1 (100:0), T2 (60:40), T3 (40:60), T4 (20:80), T5 (10:90), and T6 (0:100). The ruminal pH, total gas emission, ammonia nitrogen, and volatile fatty acid (VFA) were determined as fermentation parameters. Total nutrients digestibility trial was conducted by 4 treatments according to WCRS: concentrate ratio at 40:60 (W40), 20:80 (W20), and 10:90 (W10), respectively. Feed value was analyzed according to AOAC (2019) and nutrient digestibility was calculated based on NRC (2001). The levels of crude protein (CP), crude fat, and neutral detergent fiber of the WCRS were 12.29%, 1.67%, and 59.79%, respectively. It was found to be 51.49% as a result of predicting the total digestible nutrient of WCRS using the NRC (2001) model. In vitro rumen fermentation, T4, T5, and T6 treatments showed a greater gas emission and total VFA concentration compared with other treatments (p<0.05). Acetate and acetate to propionate ratio of T4, T5, and T6 were significantly higher than other treatments (p<0.05). There was a significant difference in the level of propionate and butyrate according to the WCRS: concentrate ratio (p<0.05). The digestibility of dry matter and CP was significantly lower in W40 than in other treatments (p<0.05); however, there was no difference in W20 and W10. In conclusion, the 20:80 (WCRS: concentrate) is beneficial for stabilizing the rumen that does not inhibit rumen fermentation and nutrient digestion. This ratio might have a positive effect on the economics of farms as a valuable feed.

ABSTRACT
Ⅰ. 서 론
Ⅱ. 재료 및 방법
    1. 공시재료 및 화학적 분석
    2. 영양소 분석 결과를 이용한 총가소화영양소(total digestiblenutrient, TDN) 예측
    3. 위액채취 및 반추위 in vitro 발효성상 분석
    4. 영양소 소화율 분석
    5. 통계분석
Ⅲ. 결과 및 고찰
Ⅳ. 요 약
Ⅴ. 사 사
Ⅵ. REFERENCES

• 박설화(농촌진흥청 국립축산과학원 영양생리팀) | Seol Hwa Park (Animal Nutrition & Physiology Team, National Institute of Animal Science, Rural Development Administration)
• 백열창(농촌진흥청 국립축산과학원 영양생리팀) | Youl Chang Baek (Animal Nutrition & Physiology Team, National Institute of Animal Science, Rural Development Administration)
• 이슬(농촌진흥청 국립축산과학원 영양생리팀) | Seul Lee (Animal Nutrition & Physiology Team, National Institute of Animal Science, Rural Development Administration)
• 김병현(농촌진흥청 국립축산과학원 영양생리팀) | Byeong Hyeon Kim (Animal Nutrition & Physiology Team, National Institute of Animal Science, Rural Development Administration)
• 류채화(농촌진흥청 국립축산과학원 영양생리팀) | Chae Hwa Ryu (Animal Nutrition & Physiology Team, National Institute of Animal Science, Rural Development Administration) Corresponding author