Determining the IgG concentrations in bovine colostrum and calf sera with a novel enzymatic assay
Bibliographic record
Abstract
BACKGROUND: Immune protection in newborn calves relies on a combination of the timing, volume and quality of colostrum consumed by the calf after birth. Poor quality colostrum with inadequate immunoglobulin concentration contributes to failed transfer of passive immunity in calves, leading to higher calf morbidity and mortality. Therefore, estimating colostrum quality and ensuring the transfer of passive immunity on farm is of critical importance. Currently, there are no on-farm tools that directly measure immunoglobulin content in colostrum or serum. The aim of this study was to apply a novel molecular assay, split trehalase immunoglobulin G assay (STIGA), to directly estimate immunoglobulin content in dairy and beef colostrum and calf sera, and to examine its potential to be developed as on-farm test. The STIGA is based on a split version of trehalase TreA, an enzyme that converts trehalose into glucose, enabling the use of a common glucometer for signal detection. In a first study, 60 dairy and 64 beef colostrum and 83 dairy and 84 beef calf sera samples were tested with STIGA, and the resulting glucose production was measured and compared with radial immunodiffusion, the standard method for measuring immunoglobulin concentrations. RESULTS: Pearson correlation coefficients between the methods were determined and the sensitivity, specificity, and accuracy of the test were calculated for different colostrum quality and failed transfer of passive immunity cut-off points. The correlations of the STIGA measured by colorimetric enzymatic reaction compared to radial immunodiffusion for dairy and beef colostrum were 0.72 and 0.73, respectively, whereas the correlations for dairy and beef sera were 0.9 and 0.85, respectively. Next, STIGA was tested in a blinded study with fresh colostrum and serum samples where the correlation coefficient was 0.93 and 0.94, respectively. Furthermore, the performance of STIGA followed by glucometer readings resulted in correlations with radial immunodiffusion of 0.7 and 0.85 for dairy and beef colostrum and 0.94 and 0.83 for dairy and beef calf serum. CONCLUSIONS: A split TreA assay was validated for measurement of the immunoglobulin content of colostrum and calf sera using both a lab-based format and in a more user-friendly format compatible with on-farm testing.
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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 | 0.005 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.001 | 0.018 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".