Short communication: Analysis of health and survival in a population of Ontario Holstein heifer calves
Notice bibliographique
Résumé
The objective of the present study was to investigate health and survival in heifer calves, from 16 farms in southwestern Ontario. Research technicians visited the farms on a weekly schedule for 16 mo, starting in January 2008, and collected blood samples and various measurements to determine the overall health status of the calves. Data of 1,588 Holstein heifer calves from birth until 90 to 120 d of age were analyzed. Initially, a survival analysis was carried out to determine which factors surrounding birth increased a calf's risk of mortality. The factors examined were type of birth, calving ease, season of birth, serum total protein, weight during first week of life, treatment status during first week of life, total number of treatments, and bovine respiratory disease status. In general, calves born in fall (October-December), low serum total protein, low weight, and calves treated for illness during the first week of life, increasing number of treatments, and being treated for bovine respiratory disease all increased a calf's risk of mortality. Genetic parameters for requiring treatment for illness, survival, bovine respiratory disease, other diseases, height, and weight were estimated. Heritabilities for treatment, survival, and diseases were low, ranging from 0.04 to 0.07, and were not significant. Moderate and significant heritabilities were found for height (0.33 to 0.45) and weight (0.24 to 0.44). Treatment and survival to 90 to 120 d of age were favorably correlated, indicating that calves requiring less treatment have a higher survival rate and vice versa. Further, body weight was found to have a tendency of favorable genetic correlation (-0.22 to -0.53) with treatment for diseases, indicating that calves with higher body weight in their first month of life were genetically more resistant to diseases than those with average body weight. Overall, our results show the potential of using data on calfhood disease and survival in future dairy cattle breeding programs. Further investigation and improved data collection are required to determine the full impact of genetics on health and survival in dairy heifer calves.
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 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 tête enseignante, 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 ».