Passive immunity and colostrum management practices on Ontario dairy farms and auction facilities: A cross-sectional study
Notice bibliographique
Résumé
Failed transfer of passive immunity (FTPI) in dairy calves has substantial health consequences, but there have been no recently published estimates of the prevalence of FTPI on Ontario dairy farms. The major objectives of this cross-sectional study were to determine the level of FTPI in dairy calves across the province of Ontario and to determine colostrum management practices used. A convenience sample of 109 dairy farms in Ontario were visited from June to August 2019, along with 4 auction facilities from January to February 2019. At the single visit to each dairy farm, an in-person questionnaire was administered, and all calves between 24 h and 9 d of age had a blood sample collected to determine the levels of serum total protein (STP). At the auction facility, a blood sample was collected on all calves that arrived on the day of the visit. The dairy farms were distributed throughout Ontario, and the farms milked on average 151 dairy cows. Of the 444 calves sampled on Ontario dairy farms, 46% were male, 54% were female, and the mean weight and age at sampling were 46.3 kg and 4.4 d, respectively. The mean STP of calves sampled on the dairy farm was 5.69 g/dL (standard deviation = 0.78), and 107 calves (24%) had FTPI. The likelihood of FTPI was not associated with sex (female vs. male, risk ratio = 0.89, 95% confidence interval = 0.64-1.24), age (per day, risk ratio = 1.02, 95% confidence interval = 0.94-1.11), or weight (per kg, risk ratio = 0.98, 95% confidence interval = 0.96-1.01). In contrast, at the auction facilities, 386 male dairy calves were sampled and had a mean STP of 5.79 g/dL (standard deviation = 0.83). Using a cut point of ≥5.2 g/dL, 91 calves (24%) had FTPI. From the in-person questionnaire administered on the dairy farms, it was reported that the median time to first feeding of colostrum was 2.5 h (range = 0-12 h). The farms reported providing a mean of 3.3, 2.9, and 3.4 L of colostrum from 0 to 6 h after birth, 6 to 12 h after birth, and 12 to 24 h after birth, respectively. Ninety-one farms (83%) fed colostrum from the dam of the calf as their predominant source of colostrum. The most common method used to deliver the first feeding of colostrum was a nipple bottle (89 farms, 82%). Twenty-seven farms (25%) reported managing colostrum differently for male calves, which included a different colostrum source, use of poorer quality colostrum, a smaller quantity of colostrum, a longer time from birth to feeding, and generally having a lower focus on colostrum management for male calves. The prevalence of FTPI on Ontario dairy farms appears to have decreased since previous estimates, and substantial room for improvement remains. Although no overall differences were found in FTPI between male and female calves, differential reported colostrum management by sex indicates this may be a risk for male calves on a proportion of Ontario dairy farms.
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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 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| 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 ».