This study was performed to investigate the effect of heat-stressed environment on rumen microbial diversity in Holstein cows. Rectal temperature and respiration rate were measured and rumen fluid was collected under normal environment (NE; Temperature humidity index (THI)=64.6) and heat-stressed environment (HE; THI=87.2) from 10 Holstein cows (60±17.7 months, 717±64.4 kg) fed on the basis of dairy feeding management in National Institute of Animal Science. The rumen bacteria diversity was analyzed by using the Illumina HiSeq™ 4000 platform. The rectal temperature and respiratory rate were increased by 1.5ﾟC and 53 breaths/min in HE compared to that in NE, respectively. In this study, HE exposure induced significant changes of ruminal microbe. At phylum level, Fibrobacteres were increased in HE. At genus level, Ruminococcaceae bacterium P7 and YAD3003, Butyrivibrio sp. AE2032, Erysipelotrichaceae bacterium NK3D112, Bifidobacterium pseudolongum, Lachnospiraceae bacterium FE2018, XBB2008, and AC2029, Eubacterium celulosolvens, Clostridium hathewayi, and Butyrivibrio hungatei were decreased in HE, while Choristoneura murinana nucleopolyhedrovirus, Calothrix parasitica, Nostoc sp. KVJ20, Anabaena sp. ATCC 33047, Fibrobacter sp. UWB13 and sp. UWB5, Lachnospiraceae bacterium G41, and Xanthomonas arboricola were increased in HE. In conclusion, HE might have an effect to change the rumen microbial community in Holstein cows.

ABSTRACT
Ⅰ. 서 론
Ⅱ. 재료 및 방법
    1. 공시동물, 사료 및 실험설계
    2. 고온 스트레스 영향 수준 측정
    3. 반추위내 미생물 균총 분석
    4. 반추위 미생물의 분류학적 구성 및 LEfSe 분석
Ⅲ. 결과 및 고찰
    1. 고온 스트레스에 따른 직장온도와 호흡수 변화
    2. 염기서열 분석 결과 및 환경온도에 따른 미생물 균총의 변화
Ⅳ. 요 약
Ⅴ. 사 사
Ⅵ. REFERENCES

• 김동현(국립축산과학원) | Dong Hyeon Kim (National Institute of Animal Science, Rural Development Administration)
• 김명후(부산대학교 동물생명자원과학과) | Myung Hoo Kim (Department of Animal Science, Pusan National University)
• 김상범(농촌진흥청) | Sang Bum Kim (Rural Development Administration)
• 하승민(국립축산과학원) | Seung Min Ha (National Institute of Animal Science, Rural Development Administration)
• 손준규(국립축산과학원) | Jun Kyu Son (National Institute of Animal Science, Rural Development Administration)
• 이지환(국립축산과학원) | Ji Hwan Lee (National Institute of Animal Science, Rural Development Administration)
• 허태영(국립축산과학원) | Tai Young Hur (National Institute of Animal Science, Rural Development Administration)
• 이재영(국립축산과학원) | Jae Yeong Lee (National Institute of Animal Science, Rural Development Administration)
• 박지후(국립축산과학원) | Ji Hoo Park (National Institute of Animal Science, Rural Development Administration)
• 최희철(국립축산과학원) | Hee Chul Choi (National Institute of Animal Science, Rural Development Administration)
• 이현정(국립축산과학원) | Hyun Jeong Lee (National Institute of Animal Science, Rural Development Administration)
• 박범영(국립축산과학원) | Beom Young Park (National Institute of Animal Science, Rural Development Administration)
• 기광석(국립축산과학원) | Kwang Seok Ki (National Institute of Animal Science, Rural Development Administration)
• 김언태(국립축산과학원) | Eun Tae Kim (National Institute of Animal Science, Rural Development Administration) Corresponding author