Short communication: Summer on-farm environmental condition assessments in Québec tiestall farms and adaptation of temperature-humidity index calculated with local meteorological data
Notice bibliographique
Résumé
Temperature-humidity index (THI) calculation following the equation developed by the National Research Council (A Guide to Environmental Research on Animals, 1971) requires ambient temperature (AT) and relative humidity (RH). Those data are widely and readily available at local meteorological stations. However, studies showed that using average AT and RH retrieved from the closest stations is not appropriate for estimating on-farm conditions. The present objectives were (1) to study summer on-farm environmental conditions, (2) to explore the relationship between summer THI calculated with on-farm data and summer THI calculated with local weather station data, and (3) to verify whether THI calculated with summer meteorological station data could be adapted to better represent summer on-farm conditions. Six tiestall dairy farms located in 2 regions of the province of Québec [Eastern Québec (EQ) and Southwestern Québec (SWQ)] were enrolled in this study. Within-barn conditions were monitored using 3 remote data loggers from August 2016 through August 2017. Two loggers were installed inside at varying distances relative to the ventilation inlet (L1: closest to inlet; L2: farthest from inlet) and a third was installed just outside of the barn (L3). Values retrieved from each logger and the closest local meteorological station were used to calculate daily THI according to the National Research Council formula and were ultimately compared. Our results showed that THI varied within the barn depending on the proximity relative to the inlet because THI measured by L1 was lower than THI measured by L2 in both regions. Moreover, our results showed that in both regions AT measured on-farm was consistently higher than AT measured at the weather station. The opposite was observed with RH, as it was significantly lower on-farm in EQ and numerically lower in SWQ compared with RH extracted from weather stations. Overall, this led to THI being lower by 4.6 and 3.7 units at the weather stations compared with within-barn conditions for EQ and SWQ farms, respectively. Hence, using local meteorological station data to estimate on-farm conditions would lead to an underestimation of heat stress level in dairy cows. Adapting THI calculations by including daily maximum AT and minimum RH retrieved from the local weather station instead of their average counterparts led to a better estimation of within-barn conditions. However, the difference between THI measured on-farm and the adapted THI calculated with weather station data remained significant. Although the adaption made to THI allowed for a closer relation to on-farm conditions, THI calculated with weather station data should only be used to assess heat stress level in dairy cows when heat stress thresholds are adapted for such data.
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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 | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,001 | 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 ».