Biosecurity practices associated with BVDV infection in dairy herds in Brazil
Bibliographic record
Abstract
This research aimed to associate biosecurity practices with the serological status of the BVDV virus in dairy production systems. Firstly, 270-290 systems were selected for virus detection between January 2020 and January 2023 using the Real-Time Polymerase Chain Reaction (real-time RT-qPCR) technique (IDEXX RealPCR BVDV RNA Test). After this stage, 68 herds were selected to identify persistently infected (PI) animals through ear biopsy and individual analysis using ELISA-antigen (IDEXX BVDV Ag/Serum Plus Test, IDEXX, Westbrook, ME, USA). All animals born to the last generation, females that gave birth to male calves or stillbirths, were tested, including the research on the generation of mothers and maternal grandmothers in positive cases. A biological risk analysis questionnaire for BVDV was applied to this group of animals. To identify associations between herds with or without BVDV circulation and biosecurity practices, multiple correspondence analysis (MCA) was used using the JMP program integrated into SAS. Using MCA, we found an association between the lack of knowledge about the disease and the perception that the herd is protected against BVDV on farms with virus circulation. On farms without viral circulation, managers knew about the disease and considered themselves unprotected from it. Herds positive for Bovine Viral Diarrhea used vaccines only for reproductive diseases, while negative herds used vaccines for respiratory and reproductive problems, suggesting possible differences in vaccination protocols and vaccine efficacy in Brazil. Biosecurity practices such as frequent visitation, contact between animals of different ages, and the annual introduction of new animals were associated with viral circulation, while virus-free herds adopted measures such as controlled visitation policies, no contact between cattle of different ages, and quarantine. In addition, positive production systems acquired pregnant females without testing the animal beforehand. Thus, this study highlights essential aspects for controlling the Bovine Viral Diarrhea virus in dairy herds, identifying that managers of negative herds have a sharper perception of risk and apply biosecurity practices that protect their herds from the main risk factors of the disease, in contrast to BVDV-positive herds.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 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".