The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39°C for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybeansupplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.

ABSTRACT
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 실험 1. In vitro 반추위 발효 특성
    2. 실험 2. 거세한우의 성장 및 육질등급
    3. 통계분석
Ⅲ. 결과 및 고찰
    1. 실험사료의 화학적 성분
    2. 실험 1. 옥수수 사일리지에 대두 사일리지의 첨가가in vitro 반추위 발효 성상에 미치는 영향
    3. 실험 2. 옥수수와 대두 혼합 사일리지 급여가 거세한우의성장 및 육질 등급에 미치는 영향
Ⅳ. 요약
Ⅴ. 사사
Ⅵ. REFERENCES

• 강주희(경북대학교 축산BT학과) | Juhui Kang (Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea)
• 이기환(경북대학교 축산BT학과) | Kihwan Lee (Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea)
• 타비타 다메리아 마분(경북대학교 축산BT학과) | Tabita Dameria Marbun (Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea)
• 송재용(경북대학교 축산학과) | Jaeyong Song (Department of Animal Science, Kyungpook National University, Sangju 37224, Republic of Korea)
• 권찬호(경북대학교 축산BT학과, 경북대학교 축산학과) | Chan Ho Kwon (Department of Animal Science and Biotechnology, Kyungpook National University,Department of Animal Science, Kyungpook National University)
• 윤두학(경북대학교 축산BT학과, 경북대학교 축산학과) | Duhak Yoon (Department of Animal Science and Biotechnology, Kyungpook National University,Department of Animal Science, Kyungpook National University)
• 서진동(경북대학교 응용생명과학부) | Jin-Dong Seo (School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea)
• 조영민(군위축산업협동조합) | Young Min Jo (Gunwi Livestock Cooperative Federation, Gunwi 39015, Republic of Korea)
• 김진열(군위축산업협동조합) | Jin Yeoul Kim (Gunwi Livestock Cooperative Federation, Gunwi 39015, Republic of Korea)
• 김은중(경북대학교 축산BT학과, 경북대학교 축산학과) | Eun Joong Kim (Department of Animal Science and Biotechnology, Kyungpook National University,Department of Animal Science, Kyungpook National University) Corresponding author