Assessment of antimicrobial transfer from treated to untreated mammary gland quarters by use of high-pressure liquid chromatography for detection of cloxacillin in milk samples from nonlactating dairy cows
Bibliographic record
Abstract
OBJECTIVE: To determine whether half-udder intramammary infusion of cloxacillin results in transfer of cloxacillin from treated to untreated mammary gland quarters within nonlactating cows, and, if so, at what concentrations, and to determine whether selection of ipsilateral versus diagonal-contralateral quarters for treatment affects cloxacillin transfer among quarters. ANIMALS: 20 Holstein-Friesian cows from a dairy herd. PROCEDURES: A within-cow half-udder comparison trial was used in which 2 of 4 mammary gland quarters (ipsilaterally or diagonally) received an intramammary infusion of cloxacillin on day 1 of the nonlactating period. Three days later, milk samples were taken from all untreated quarters and high-pressure liquid chromatography was used to detect and quantify milk cloxacillin concentrations. RESULTS: Cloxacillin was detected in 25% of all untreated mammary gland quarters. Mean cloxacillin concentration in untreated quarters was below minimum inhibitory concentrations for targeted mastitis pathogens. No significant difference in cloxacillin concentrations was found in the ipsilateral or diagonal treatment groups. CONCLUSIONS AND CLINICAL RELEVANCE: Within-cow half-udder comparison trials are valid for antimicrobial trials in nonlactating cows, although transfer of antimicrobials does occur in trace concentrations. Ipsilateral or diagonal-contralateral treatment designs perform similarly. This type of design is economical for researchers, although care must be taken to account for within-cow clustering of mammary gland quarter data.
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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 | 0.001 | 0.001 |
| 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) | 0.001 | 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".