612 Effects of the seaweed Ascophyllum nodosum on the rumen microbiome and fecal pathogenic Escherichia coli serotypes in sheep
Bibliographic record
Abstract
Feeding rams Tasco® (SW), a high quality, sun-dried seaweed meal produced from the brown macroalga Ascophyllum nodosum, reduced Escherichia coli O157:H7 shedding in feces without affecting rumen fermentation. The effects of SW on the microbiota and other pathogenic E. coli O-serotypes in the rumen have not been extensively studied. The current study aimed to evaluate the effects of Tasco® at different feeding levels on the rumen microbiome as well as the presence of non-O157 E. coli serotypes. A 4 × 4 Latin square design used 8 ram lambs randomly allocated to diets containing 0%, 1%, 3%, or 5% of the diet DM as SW. Rumen contents and feces were collected, DNA was extracted, and 16S rRNA was sequenced to study the ecology of bacterial and archaeal communities using QIIME. Functional pathways were predicted using PICRUSt, and seven E. coli serotypes were measured using multiplex PCR. Feeding SW linearly (P < 0.001) lowered the total rumen bacterial population (log10 16S rRNA gene copies/g) from 11.63 in Con to approximately 10.50 and linearly reduced (P < 0.001) the total archaeal population from 8.70 to 8.13. Different SW levels did not affect the overall bacterial and archaeal profiles or the microbial diversity indices, with substantial variation in these parameters among individual rams. Relative abundance of three bacteria phyla, five bacteria families, and seven species differed among SW levels. There were 14 enriched metabolic pathways in SW-fed rams, while only 3 pathways were suppressed by SW feeding. A VFA profile with a higher acetate molar portion (P < 0.001) and a lower propionate (P < 0.001) and butyrate (P < 0.001) molar portion was seen with SW supplement, and the lower butyrate can be associated with the enrichment of the “Butanate metabolism' pathway in the SW-fed rams. Total E. coli population within the rumen was linearly reduced (P < 0.001) by SW from 6.82 (log10 16S rRNA gene copies/g) in Con to 6.27, 5.86, and 5.90 with the three SW levels. Including SW only completely eliminated O121 in the rumen and the feces, but O45, O103, and O111 were also eliminated in the feces, although they were detected in the rumen.
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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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".