120 After all, tomorrow is another day for the transition cow: Depending on liver and reproductive health, of course
Notice bibliographique
Résumé
Infertility in lactating dairy cows has been attributed to metabolic stress during the transition period. Potential metabolic alterations that dysregulate ovarian functions have not been completely cataloged. Our objective was to characterize metabolic parameters of dairy cows during the transition period. First, we examined the metabolic profiles in circulation to pinpoint time points of major changes. We collected weekly blood samples from Holstein cows (N = 15) from 3 wk before to 12 wk after calving. Glucose levels reduced during pre-calving weeks to reach a nadir at 3 wk post-calving (P < 0.05), and the first increase in glucose concentration occurred at 10 wk post-calving (P < 0.05). Also, β-hydroxybutyric acid levels increased from calving until week 3 of lactation (P < 0.05) and subsequently returned to baseline. Levels of triglycerides decreased during pre-calving weeks, while significant increase occurred at 5 wk post-calving (P < 0.05). Total cholesterol concentrations increased from the third to seventh week post-calving (P < 0.05). Oxidative stress indicator, glutathione, decreased to reach a nadir by 7 wk in lactation (P < 0.05). Thus, post-calving weeks 3 to 7 are associated with major alterations in metabolic indicators in circulation. In the second experiment, we evaluated changes in hepatic and granulosa cell (GC) mRNA levels and circulating metabolic indicators during the periods of major metabolic changes listed above. We collected blood and liver biopsies from Holstein cows at 3 wk pre-partum, during calving week, and 7 wk post-partum; this last liver sample accompanied collection of GCs from the dominant follicle by follicular aspiration. Cows were separated into two groups, where Group 1 (N = 4) consisted of cows that lost less than 0.75 body condition score (BCS) during the sampling trial and Group 2 (N = 4) consisted of cows that lost equal to or greater than 0.75 BCS. Lipid metabolism and oxidative stress were evaluated in hepatic tissue by qPCR. Transcript abundance revealed a decrease in CYP7A1 (P < 0.05) and tendency for decrease of LDLR (P < 0.1) in cows from Group 2 at 3 wk pre-partum. Transcript abundance of SRB1, ACAT1, PON1, and APOB100 remained unaltered between groups at all time points (P > 0.05). Assessing reproductive competence through mRNA abundance of genes required for growth and ovulation (SRB1, FSHR, and LHR) in GCs remained unchanged (P > 0.05). Taken together, transition period features increasing cholesterol, triglycerides and decreasing glucose and glutathione compared to pre-calving period. Further studies, including liver function assays, are required to thoroughly investigate the relationship between liver health, reproductive health, and alterations in circulating metabolic indicators.
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 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 | 0,002 | 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 | 0,000 |
| 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 ».