Effect of dietary factors on distribution and chemical composition of liquid- or solid-associated bacterial populations in the rumen of dairy cows.
Bibliographic record
Abstract
Effects of dietary factors including kernel thickness of processed barley grain, ratio of forage to concentrate, and forage particle length on chemical composition of bacteria, bacterial colonization of feed particles and distribution in the rumen, and duodenal flow of bacteria in dairy cows were evaluated. The experiment was designed as a double 4 x 4 quasi-Latin square with a 2 x 2 x 2 factorial arrangement of treatments using eight lactating cows with ruminal and duodenal cannulas. Barley grain was steam-rolled to two thicknesses: coarse (1.60 mm) or flat (1.36 mm); ratio of forage:concentrate was low (35:65) or high (55:45) (DM basis); and forage particle length was long (7.59 mm) or short (6.08 mm). Cows were offered ad libitum access to a total mixed diet. Chemical composition was different (P < 0.01) between liquid-associated bacteria (LAB) and solid-associated bacteria (SAB). Reduced barley thickness increased (P < 0.05) N content and 15N enrichment, but a high ratio of forage:concentrate decreased (P < 0.01) 15N enrichment of both the LAB and SAB. Significant differences between AA composition of the LAB and SAB were observed for 15 out of 17 AA studied. Bacterial colonization was linearly increased (P < 0.01) from about 5 to 70% as particle length of rumen contents was reduced from 3.35 mm to 0.15 mm (sieve size). The degree of colonization on each fraction of the rumen particulate matter was only affected (P < 0.10) by the ratio of forage:concentrate, with consistently higher (P < 0.10) bacterial colonization noted for high than for low forage:concentrate diets. Of the total bacterial mass within the rumen, less than 20% was associated with the liquid and over 70% was associated with the small particles that passed through the 0.6-mm sieve. Although the bacterial pool in the rumen was lower (P < 0.04) when flatly rolled barley rather than coarsely rolled barley was fed, bacterial flow to the duodenum was greater (P < 0.10) with increasing ratio offorage:concentrate. The present results confirm the differences of chemical composition and biomass for LAB and SAB. Manipulation of dietary factors such as ratio of forage:concentrate have the potential to alter bacterial colonization of rumen particles and the relative proportion of LAB to SAB, which were positively correlated to bacterial flow to the duodenum.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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) | 0.000 | 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 teacher head, 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".