Weaning stress is the most common issue in weanling pigs, and increases diarrhea and mortality. Various wavelengths of light irradiation affect the body owing to the association with biophotons. Biophotons are very weak photons in the visible light range generated during metabolic and chemical reactions in vivo. Immune mechanisms are activated by increasing signal transmission between cells through biophoton emission. This study evaluated the influence of ultra-weak light (LED) on growth performance, antioxidant status, and stress of weaned piglets. A total of 120 weaned pigs with an average initial body weight of 7.04±0.01 kg (age: 21 d) were allotted to two treatments (Control and LED) with 10 replicates. Diets prepared in pellet form were administered to the pigs in three phases including Phase 1 (0–14 d), Phase 2 (15–28 d), and Phase 3 (29–42 d). At the end of the study, the average daily gain (8.96%, p<0.05) and feed efficiency (6.56%, p<0.05) of pigs was significantly increased at phase 3 in the LED treatment. Low concentration of malondialdehyde (12.58%, p<0.05) and high concentrations of glutathione reductase (7.41%, p<0.01) and total antioxidant capacity (5.48%, p<0.05) were observed in the LED treatment at Day 42. The concentration of hair cortisol was also decreased (24.05%, p<0.05) in the LED treatment at Day 42. In conclusion, the use of LED for weanling pigs is recommended to improve growth performance by modulating antioxidant capacity and cortisol level in hair.

Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 광조사
    2. 시험설계, 공시동물 및 사양관리
    3. 사양성적
    4. 혈액 성상
    5. 통계적 분석
Ⅲ. 결과 및 고찰
    1. 사양성적
    2. 항산화 활성
    3. Hair cortisol 수준
Ⅳ. 요약
Ⅴ. 참고문헌

• 박세린(강원대학교 동물생명과학대학 동물산업융합학과 대학원생) | Se Rin Park (Graduate student, Department of Animal Industry Convergence, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea)
• 문준영(강원대학교 동물생명과학대학 동물산업융합학과 대학원생) | Jun Young Mun (Graduate student, Department of Animal Industry Convergence, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea)
• 하상훈(강원대학교 동물생명과학대학 동물산업융합학과 대학원생) | Sang Hun Ha (Graduate student, Department of Animal Industry Convergence, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea)
• Tajudeen Habeeb Temitope(강원대학교 동물생명과학대학 동물산업융합학과 대학원생)
• Hossindoust Abdolreza(강원대학교 동물생명과학연구소 연구원)
• 박미정(㈜바이오라이트 대표이사) | Mi Jeong Park (Representative director, Biolight Corporation, Hanam 12982, Korea)
• 김진수(강원대학교 동물생명과학대학 동물산업융합학과 교수) | Jin Soo Kim (Professor, Department of Animal Industry Convergence, College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea) Corresponding author