biostudies-literatureUnknown11Zhang JThis study aimed to investigate the effects of fermented soybean meal (FSM) on milk production, blood parameters, and rumen fermentation and microbial community in dairy cows. In this study, 48 healthy Holstein cows (parity, 3.0 ± 0.6; days in milk, 86.0 ± 6.7) were used. Cows were randomly assigned into four groups (CON, T-200, T-400, and T-600) with 12 cows per group. Cows in CON were not supplemented with FSM. Cows in T-200, T-400, and T-600 were supplemented with 200, 400, and 600 g/head/day FSM, respectively. This study lasted 5 weeks (1-week adaptation and 4-week treatment). The results showed that FSM did not affect milk yield and milk components (<i>p</i> > 0.05). In the serum, FSM greatly increased prolactin (<i>p</i> < 0.01), and a dosage effect was observed. Aspartate aminotransFrontiers in veterinary science1498639https://www.ebi.ac.uk/biostudies/studies/S-EPMC11599173biostudies-literatureFermented soybean meal modified the rumen microbiota and increased the serum prolactin level in lactating Holstein cows.PMC11599173Huang SJin WMao SZhang JGuan FMa YWen SfalseFermented soybean meal modified the rumen microbiota and increased the serum prolactin level in lactating Holstein cows.This study aimed to investigate the effects of fermented soybean meal (FSM) on milk production, blood parameters, and rumen fermentation and microbial community in dairy cows. In this study, 48 healthy Holstein cows (parity, 3.0 ± 0.6; days in milk, 86.0 ± 6.7) were used. Cows were randomly assigned into four groups (CON, T-200, T-400, and T-600) with 12 cows per group. Cows in CON were not supplemented with FSM. Cows in T-200, T-400, and T-600 were supplemented with 200, 400, and 600 g/head/day FSM, respectively. This study lasted 5 weeks (1-week adaptation and 4-week treatment). The results showed that FSM did not affect milk yield and milk components (<i>p</i> > 0.05). In the serum, FSM greatly increased prolactin (<i>p</i> < 0.01), and a dosage effect was observed. Aspartate aminotrans2024-01-01T00:00:00Z20242026-06-01T07:39:41.993Z2025-04-21T21:46:40.693ZS-EPMC115991733960665510.3389/fvets.2024.1498639