@article{oai:iwate-u.repo.nii.ac.jp:00015709,
 author = {石塚, 直樹 and Kim, Yohan and 岩本, 英治 and 正木, 達規 and 木村, 淳 and 一條, 俊浩 and 佐藤, 繁},
 issue = {2},
 journal = {産業動物臨床医学雑誌, Japanese Journal of Large Animal Clinics},
 month = {Aug},
 note = {黒毛和種牛の肥育後期における第一胃液の性状，液相・固相の細菌叢構成と枝肉成績との関係を明らかにする目的で，第一胃液のpH，揮発性低級脂肪酸（VFA），アンモニア態窒素（NH₃-N），乳酸（LA），リポポリサッカライド（LPS）および液相と固相の細菌叢構成を解析し，肥育および枝肉成績との関係を検討した．第一胃フィステルを装着した黒毛和種去勢牛9 頭を供試し，第一胃液pH は無線伝送式pH センサを用いて測定した．29 カ月齢時に第一胃内容を採取し，二重滅菌ガーゼを用いて液状部（液相）と食渣部（固相）に区分した．液相の各種性状のほか，液相と固相の細菌叢構成を次世代シークエンス法により解析した．また，屠殺解体（平均30.5 カ月齢）後，胸最長筋内脂肪を採取し，ガスクロマトグラフ法により脂肪酸組成を測定した．
 その結果，第一胃液pH は平均5.67 と低値を示し，LPS 活性値は平均6.62 × 104 EU/mℓと高値を示した．細菌叢構成では，液相と固相のいずれもFirmicutes 門，Bacteroidetes 門およびActinobacteria 門の構成比が高かった．種レベルではLactonifacter longoviformis とOlsenella umbonata の構成比が高く，固相では液相に比べて，Succiniclasticum ruminis とMogibacterium neglectum の構成比が高値を示した．脂肪酸組成はC18：1，C16：0，C18：0，C16：1 の順に多く，一価不飽和脂肪酸（MUFA）は57.46 %，多価不飽和脂肪酸（PUFA）は2.22 %，飽和脂肪酸（SFA）は40.32 % であった．第一胃液pHとC16：1およびC18：1組成比との間に有意な正の相関が認められ，高MUFA群では低MUFA 群に比べて第一胃液pH が高値で推移する傾向がみられた．
 以上のことから，黒毛和種去勢牛の肥育後期における第一胃細菌叢構成は，液相と固相で差異があり，また，固相の細菌叢構成は液相に比べて筋肉内脂肪中MUFA 組成や皮下脂肪厚との間で有意な相関が多いことが示唆された．, We investigated rumen fermentation parameters, such as rumen pH, volatile fatty acid（VFA）, ammonia nitrogen（NH3-N）, lactic acid（LA）, lipopolysaccharide（LPS）and the rumen bacterial community to elucidate relationships among rumen fermentation, bacterial composition in the liquid and solid fractions of rumen content and meat quality in Japanese Black beef cattle in the late fattening stages. Nine castrated（5 to 6 months old）and subsequently fistulated（at 12 months old）Japanese Black beef cattle were used. Rumen pH was measured continuously every 10 minutes using a radio transmission pH measurement system. Rumen content samples were collected at 29 months of age and filtered through two layers of cheesecloth to separate the liquid and solid fractions. Rumen fermentation parameters were measured using liquid rumen samples. Total bacterial DNA was extracted from the liquid and solid samples for paired-end sequencing of the V4 hypervariable region using an Illumina MiSeq platform. Fatty tissues in the thoracic longissimus muscle were collected after slaughter（on average 30.5 months old）, and the fatty acid profile was analyzed by gas chromatography.
 The mean rumen pH was low（5.67）and the rumen LPS activity was high（6.62 × 104 EU/mℓ）during the late fattening stage. At the phylum level, Firmicutes had the greatest relative abundance, followed by Bacteroidetes and Actinobacteria, for both liquid and solid fractions. At the species level, Lactonifacter longoviformis had the greatest relative abundance, followed by Olsenella umbonata, for both liquid and solid fractions, while Succiniclasticum ruminis and Mogibacterium neglectum were relatively more abundant in the solid fractions than in the liquid fractions. In the fatty acid analysis, C18：1 was most abundant, followed by C16：0, C18：0 and C16：1. Monounsaturated fatty acids（MUFA）accounted for 57.46% of the total fatty acids, polyunsaturated fatty acids（PUFA）for 2.22% and saturated fatty acids（SFA）for 40.32%. Rumen pH was significantly positively correlated with the proportions of C16：1 and C18：1, and a relatively higher rumen pH was observed in the high MUFA group compared with the low MUFA group.
 Collectively, these results suggest that the bacterial composition is different between the liquid and solid fractions of ruminal content at the species level and that the bacterial composition of the solid fraction may affect the proportion of MUFA and thus meat quality in Japanese Black beef cattle at the late fattening stage.},
 pages = {66--76},
 title = {黒毛和種牛の肥育後期における第一胃内細菌叢構成と肥育および枝肉成績の関係},
 volume = {11},
 year = {2020}
}