Intranasal zinc and vitamin A treatments alter response to bovine respiratory syncytial virus and <i>Mannheimia haemolytica</i> co-infection
Bibliographic record
Abstract
Abstract During disease, there may be increased local demands for zinc (Zn) and vitamin A to support pathogen response. This study evaluates the effects of intranasal Zn and vitamin A treatments on steers experimentally infected with bovine respiratory disease (BRD) pathogens, bovine respiratory syncytial virus (BRSV) and Mannheimia haemolytica, hypothesizing that steers treated with Zn and vitamin A (VA) will have improved recovery to BRD challenge. Forty-eight Angus crossbred steers (333 ± 4.2 kg) were utilized in two groups with identical challenge timelines. The day prior to challenge (d −1), steers were shipped for 6 hours. On d 0, steers were administered an aerosol inoculation with ~104 TCID50/mL BRSV strain 375 followed by an intratracheal inoculation with M. haemolytica (1.42 × 108 CFU strain D153, serotype A1) on d 5. On d 4, steers received intranasal treatments: zinc (IN ZN; 50 mg Zn oxide nanoparticles), vitamin A (IN VA; 200,000 IU as retinyl palmitate), a combination of zinc (50 mg) and vitamin A (200,000 IU; IN VA + ZN) or no treatment (CON). Statistics were analyzed using the Mixed procedure of SAS 9.4 (Cary, NC) and contrast statements were utilized to determine the effects of Zn, VA and intranasal treatment. Disease challenge resulted in mostly mild, subclinical signs of disease. There was an interaction for plasma VA (TRT × Day P < 0.01) where VA treated steers (IN VA and IN VA + ZN) had sustained plasma VA concentrations on d 5, when ZN and CON had decreased plasma VA. After challenge (d 19), liver VA concentrations were increased in IN VA (IN VA P = 0.03) and IN ZN (IN ZN P = 0.05) treated steers. Zn treated steers (ZN and ZN + VA) tended to have increased gene expression of matrix metalloproteinase 9 (P = 0.06) on d 5 and cellular retinol binding protein 1 (P = 0.08) on d 7 in cells collected from nasopharyngeal swabs. Additionally, immune cell populations from bronchoalveolar lavage were altered with increased CD11b expression on neutrophils (IN VA P = 0.01) and CD11c on macrophages (IN ZN P = 0.08) on d 7. During a mild disease challenge, intranasal Zn and VA treatments impacted lung inflammatory environment and nutritional immunity, suggesting potential benefits in mild or deficient nutritional statuses.
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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) | 0.000 | 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 | 0.001 |
| 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".