613 Humic substances supplementation reduces ruminal methane production and increases the efficiency of microbial protein synthesis in vitro
Bibliographic record
Abstract
The effects of humic substances (HS) on rumen fermentation and methane (CH4) production were investigated using an in vitro rumen batch culture technique. HS was included in cultures with a 60% barley silage: 40% concentrate diet (dry matter (DM) basis) at 0, 108, 216, 324, or 432 mg HS/g of substrate incubated. Rumen in vitro batch cultures were conducted as a completely randomized design with three runs. Gas (GP) and CH4 production were measured after 3, 6, 9, 12, 24, and 48 h of incubation. Total volatile fatty acid (TVFA), microbial nitrogen (MN), and ammonia nitrogen (NH3-N), as well as disappearances of true dry matter (TDMD), neutral detergent fiber (NDFD), starch (SD), and nitrogen (ND) were determined after 12 and 48 h. Total GP was linearly increased (P < 0.05) with increasing HS inclusion during the first 12 h of incubation, but it was not affected (P > 0.05) after 24 and 48 h. Increasing HS linearly decreased (P < 0.05) CH4 production (expressed as ml/g DM) at all time points evaluated. After 48 h of incubation, CH4 production was reduced by 12.83% at the highest HS dose compared to control. Increasing HS linearly decreased NH3-N concentration, and the molar proportion of acetate (P < 0.05) at 12 h of incubation, while MN, TDMD, and the molar proportion of butyrate linearly increased (P < 0.05) and SD responded quadratically (P < 0.05). After 12 h, ND, NDFD, TVFA, the molar proportion of branched-chain VFA, and A:P ratio were not affected (P > 0.05) by increasing HS. After 48 h, HS linearly increased (P < 0.01) MN (35.15%), TDMD (7.31%), and the molar proportion of butyrate but did not affect (P > 0.05) ND, SD, the molar proportion of acetate, propionate and branched-chain VFA, A:P ratio, or NH3-N concentration. Increasing HS resulted in quadratic response (P < 0.05) in NDFD after 48 h. Overall, inclusion of HS effectively reduced CH4 production and increased in vitro substrate disappearance and the efficiency of microbial protein synthesis. Further studies are needed to evaluate the effects of HS on in vivo ruminal fermentation, CH4 production, the microbiome, and its consequent effect on growth performance.
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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 | 0.000 | 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".