Gastrointestinal permeability and inflammatory status of preweaning dairy calves in response to decreasing the ratio of n-6 to n-3 fatty acid in milk replacer
Bibliographic record
Abstract
The ratio of n-6 to n-3 fatty acid (FA) is between 2 and 10 times higher in milk replacer (MR) than in whole milk, which may promote inflammation and compromise the integrity of the intestinal epithelium. To evaluate how decreasing the n-6:n-3 FA ratio of MR affects gastrointestinal (GIT) permeability and inflammatory status, 30 dairy calves (2.8 ± 1.06 d of age; mean ± standard deviation) were randomly assigned to be fed an MR with an n-6:n-3 FA ratio of 40:1 (CON; 29.3% crude fat of DM; n = 15) or 6.5:1 (n-3; 29.1% crude fat of DM; n = 15). Calves were fed 7.0 L/d in 2 meals. Calves were weighed and fecal consistency was analyzed weekly. On d 22, calves were administered Cr-EDTA, lactulose, and d-mannitol to assess GIT permeability. Blood and total urine were sequentially collected for 6 and 24 h, respectively, and analyzed for marker content. Whole blood collected 4 h after the meal was subjected to an ex vivo lipopolysaccharide (LPS) challenge to evaluate cytokine secretion from blood cells. Calves were euthanized on d 25 for collection of intestinal tissue samples. Tissue samples were processed to assess FA composition by gas chromatography, histomorphology by bright-field microscopy, and gene expression of tight junction proteins, lipid metabolism enzymes, and immune molecules by real-time quantitative PCR. Data were analyzed using PROC GLIMMIX in SAS (version 9.4, SAS Institute Inc.). Growth performance and fecal consistency were unaffected. Calves fed MR with a lower ratio of n-6 to n-3 FA had 2-fold higher n-3 FA contents and 2-fold lower ratios of n-6 to n-3 FA in proximal jejunum and ileum tissues. Total urinary recovery (0-24 h relative to marker administration) and plasma concentrations of the markers were unaffected. Expression of TJP1 tended to be higher in proximal jejunum tissue and lower in ileum tissue of n-3 calves. The expression of TLR4 and TNFA tended to be higher and CD14 was higher in ileum tissue of n-3 calves. Plasma concentrations of interleukin-4 were decreased in response to the ex vivo LPS challenge in n-3 calves. Histomorphology and GIT permeability were largely unaffected by treatment. Furthermore, the inclusion of linseed and algae oil may promote inflammation, as suggested by greater concentrations of the acute-phase proteins haptoglobin and serum amyloid A postprandially, demonstrating that fat sources should be evaluated for their suitability for MR formulations. Understanding how MR composition affects dairy calf health may improve nutritional strategies on farm.
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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 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| 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".