Prevalence of antibodies to Bovine Leukemia virus, Neospora caninum and risk factors, and biosecurity practices in beef cow-calf herds in Canada.
Notice bibliographique
Résumé
A total of 4,778 cows from 179 herds were tested for antibodies to N. caninum using a commercially available ELISA. Neospora caninum herd-level seroprevalence ranged from 25.0% to 75.9% (a herd was considered positive with ≥ 2 cows testing positive). The true cow prevalence was estimated as 5.2% (95% CI= 4.6 – 5.8). "Pre-calving use of dry lots," "separation of cow-calf pair from other cows after calving," "use of standing water in summer," "use of running water in winter," "feeding heifers with manure handling equipment," "abortion and stillbirths left for canids" and "number of sightings of wild canids per year (categorized into three categories: less than 10 times per year, 11 – 25 times per year, and greater than 26 times per year) were positively associated with herd serological status. However, "washing boots between visits to livestock farms" was negatively associated with serological status. These 8 variables were included in a multivariable logistic regression model. Province and herd size were considered potential confounders and kept in the model regardless of significance. Only 4 variables remained significant in the final model. Risk factors associated with prevalence included the use of dry lots/corrals as pre-calving area (OR=2.8; 95% CI =1.3 – 6.2), the use of natural standing water in summer (OR=3.2; 95%CI=1.31 – 8.0), and leaving abortions/stillbirths for dogs or wild canids (OR=2.5; 95%CI=1.0 – 5.9). As the frequency of sighting coyotes and foxes increased so did herd seroprevalence to N. caninum. Risk factors suggested the likely role of horizontal transmission in the transmission of N. caninum in these beef cow-calf herds. Beef herd managers might consider biosecurity practices such as preventing the access of wild canids to fetuses and stillbirths thereby preventing pasture contamination and controlling contamination of water source with oocyst of N. caninum thereby reducing chances of infection. A herd was considered positive for Bovine leukemia virus (BLV) if ≥ 1 animal tested positive. Estimates of cow-level seroprevalence was 1.01% (95% CI= 0.73% – 1.29%) while herd seroprevalence was 12.4% (95% CI= 7.57 – 17.23). Potential risk factors examined for BLV transmission included the use of blade or surgical castration without disinfection between animals, using gouger and saw dehorning methods, multi-use of common rectal sleeve between cows without disinfection and the use of communal pasture where mating occurred. No associations existed between potential risk factors and seropositivity to BLV because the number of herds testing positive to BLV were too few to find any association. However, management practices observed in this study may have the potential to transmit infections. Lapses in biosecurity practices identified were addition of new animals to the herds (73.7%, 132/179), the use of communal grazing (24.0% (43/179) of herds using with 28% (12/43) using more than one communal pasture where mating occurred (93%, 40/43) with bulls from other herds. During communal grazing, contact herds ranged between 1 and 25 (mean = 7.4). Large herds (≥111) animals were more likely to use communal pasture compared to medium sized or small herds (≤46) (P<0.01).
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».