This study was conducted to determine the effects of dietary protein level and supplementation of protease on growth performance, nutrient digestibility, gut microflora, intestinal morphology and fecal noxious gas emission in weanling pigs. A total of 240 weaned pigs (Landrace×Yorkshire×Duroc, 5.82±0.3 kg) were used during 4 weeks in 2 phases (days 0-14, phase 1; and days 15-28, phase 2) feeding program based on age and initial body weight. Pigs were allocated to 2×2 factorial arrangement, including 2 protein levels (HP, high protein; LP, low protein) and 2 protease levels (with or without protease). The average daily gain in the LP treatment (357 g/d) was increased rather than the HP treatment (339 g/d). A greater avarage daily gain was observed in dietary suppiemented protease treatment (358 vs 339 g/d). Average feed intake was greater in the LP treatment (544 g/d) rather than the HP treatment (530 g/d). A greater average daily feed intake was observed in dietary supplemented protease treatment (552 vs 523 g/d). Dry matter and crude protein digestibility were increased in dietary supplemented protease treatment (82.62% and 76.08%, respectively) rather than non-supplemented treatment (81.74% and 75.13%, respectively). Ileal Lactobacillus spp. count increased in dietary supplemented protease treatment (7.42 vs 7.32 log10CFU/g). Emission of H2S was decreased in the LP treatment (4.41 ppm) rather than HP treatment (4.78 ppm). Emission of NH3 was decreased in dietary supplemented protease treatment (10.43 ppm vs 11.76 ppm). In conclusion, the decrease of dietary protein level and supplementation of protease had beneficial effects on growth performance, nutrient digestibility, gut microflora, and noxious gas emission in weanling pigs.

ABSTRACT
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 시험설계, 공시동물 및 사양관리
    2. 사양성적
    3. 영양소 소화율
    4. 장 내 미생물
    5. 소장 내 융모의 형태학적 변화
    6. 분내 유해가스
    7. 통계적 분석
Ⅲ. 결과 및 고찰
    1. 사양성적
    2. 영양소 소화율
    3. 장 내 미생물
    4. 소장 내 융모의 형태학적 변화
    5. 분내 유해가스
Ⅳ. 요약
Ⅴ. 참고문헌

• 하상훈(강원대학교 바이오헬스융합학과) | Sang Hun Ha (Department of Bio-Health Convergence, Kangwon National University)
• 최요한(농촌진흥청 국립축산과학원 양돈과) | Yo Han Choi (Swine Science Division, National Institute of Animal Science, R.D.A)
• Abdolreza Hossseindoust(강원대학교 바이오헬스융합학과)
• 하동진(㈜CTC바이오 애니멀헬스) | Dong Jin Ha (CTCBIO Animal Health)
• Joseph Moturi(강원대학교 바이오헬스융합학과)
• 문준영(강원대학교 바이오헬스융합학과) | Jun Young Mun (Department of Bio-Health Convergence, Kangwon National University)
• Tajudeen Habeeb(강원대학교 바이오헬스융합학과)
• 이창번(강원대학교 동물산업융합학과) | Chang Beon Lee (College of Animal life sciences, Kangwon National University)
• 박종완(강원대학교 바이오헬스융합학과) | Jong Wan Park (Department of Bio-Health Convergence, Kangwon National University)
• 김진수(강원대학교 바이오헬스융합학과) | Jin Soo Kim (Department of Bio-Health Convergence, Kangwon National University)
• 사수진(㈜CTC바이오 애니멀헬스) | Soo Jin Sa (wine Science Division, National Institute of Animal Science, R.D.A) Corresponding author