Supplementation with live yeast increases rate and extent of in vitro fermentation of nondigested feed ingredients by fecal microbiota
Bibliographic record
Abstract
Two studies were conducted to investigate the effect of live yeast (LY) on the in vitro fermentation characteristics of wheat, barley, corn, soybean meal (SBM), canola meal, and distillers dried grains with solubles (DDGS). In Study 1, LY yeast was added directly to in vitro fermentations inoculated with feces from lactating sows, whereas as in study 2, feces collected from lactating sows fed LY as a daily supplement was used. Selected feedstuffs were digested and the residue added to separate replicated (n = 3) fermentation reactions. Study 1 was conducted in two blocks, whereas study 2 was conducted using feces collected after a period of 3 (Exp. 1) or 4 wk (Exp. 2) of LY supplementation. Accumulated gas produced over 72 h was modeled for each substrate and the kinetics parameters compared between LY and control groups. The molar ratio of the volatile fatty acids (VFAs) produced in vitro were also compared at 12 and 72 h of incubation. In study 1, in vitro addition of yeast increased (P < 0.001) the rate of gas production (Rmax). However, a yeast × substrate effect (P < 0.05) observed for total gas accumulated (A), time to half asymptote (B), and time required to reach maximum rate of fermentation (Tmax) suggested that yeast-mediated increases in extent and rate of fermentation varied by substrate. Greater total gas production was observed only for corn and SBM, associated with greater B and Tmax. Supplementation with LY appeared to increase A and Rmax although with variation between experiments and substrates. In Exp. 1, LY decreased (P < 0.05) B and Tmax. However, a yeast × substrate effect (P < 0.05) was observed for only A (for wheat, barley, corn, and corn DDGS) and Rmax (wheat, barley, corn, and wheat DDGS). In Exp. 2, LY increased (P < 0.0001) A and decreased B. However, an interaction (P < 0.05) with substrates was observed for Rmax (except SBM) and Tmax. With exception of the DDGS samples, LY supplementation increased (P < 0.05) VFA production at 12 and 72 h of incubation. Yeast increased (P < 0.05) the molar ratios of acetic acid and branch-chain fatty acids at 12 h of incubation; however, this response was more variable by substrate at 72 h. In conclusion, LY supplementation increased the rate and extent of in vitro fermentation of a variety of substrates prepared from common feedstuffs. Greater effects were observed when LY was fed to sows than added directly in vitro, suggesting effects on fermentation were not mediated directly.
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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) | 0.001 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".