PSI-13 Effects of a Postbiotic Program Consisting of Liquid and Solid <i>Saccharomyces Cerevisiae</i> Fermentation Products on Ruminal Microbiome Composition and Microbial Functions of Finishing Beef Steers
Bibliographic record
Abstract
Abstract We assessed the effects of a postbiotic program consisting of liquid and solid Saccharomyces cerevisiae fermentation products (SCFP) on the ruminal microbiome and fermentation characteristics of beef steers. Eight Holstein steers (BW 467 ± 13.9 kg) with rumen cannulas were used in a crossover design study with 21-d per period and 7-d washout in between periods. Steers were blocked based on initial BW and assigned to one of two treatments: 1) Control, basal diet, or 2) SCFP, basal diet plus one day feeding of LiquiCare RTU (Diamond V, Cedar Rapids, IA; dosed via rumen cannula at 11 mL/100 kg BW), followed by daily feeding of 12 g/d NaturSafe (Diamond V, top-dressed). Rumen fluid samples were collected on d 0, 1, 2, 3, 5 and 21 at 0, 4, 8, or 12 h post morning feeding via rumen cannula for pH, VFA and NH3-N analyses. Samples collected at 4 h post morning feeding on d 0, 2 and 21 were subjected to DNA extraction and shotgun Nanopore sequencing to determine microbiome composition and carbohydrate active enzymes (CAZy) functional potential. Statistical model included the fixed effects of treatment, period, day and their interactions and random effect of animal. Feeding SCFP tended to reduce ruminal lactate (0.09 vs. 0.02 mM, P = 0.10), and reduced ruminal NH3-N (4.86 vs. 6.83 mg/dL, P = 0.04) on d 21. Ruminal total VFA concentration was increased (P = 0.01) by feeding SCFP 4-h post-feeding on d 5 and numerically increased 4-h post-feeding on day 21 (133.3 vs. 151.2 mM, P = 0.12). Treatments did not affect species or CAZy alpha- and beta-diversity. Steers received liquid postbiotic on d 2 exhibited a positive correlation (P < 0.05) between propionate molar proportion and glycosyl transferases (GT), glycoside hydrolases (GH), carbohydrate esterases, and carbohydrate binding modules (CBM); and a negative correlation (P < 0.05) between acetate molar proportion and polysaccharide lyases, GT, GH, and CBM, which was not observed in Control. Additionally, SCFP steers had higher (P = 0.05) CBM functional potential on d 21 than on d 0, while CAZy class abundances did not change over time in Control steers. Differential network analysis indicated a greater normalized degree for GT in the SCFP steers compared with Control on d 21. There were 2, 6 and 12 differently abundant species (P < 0.01) between SCFP and Control on d 0, 2 and 21, respectively, suggesting supplementing SCFP altered the abundances of more species over time. Our results showed that the postbiotic program altered the metabolic pathways of ruminal microbes toward greater propionate production, and improved abundance of carbohydrate binding modules. Our results also showed that glycosyl transferases had a greater promotive role in the ruminal enzymatic network of SCFP steers.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".