Concentration of progesterone during the development of the ovulatory follicle: I. Ovarian and embryonic responses
Notice bibliographique
Résumé
Objectives were to evaluate the effects of differing progesterone concentrations during follicle development on follicular dynamics, fertilization, and embryo quality. Lactating Holstein cows (n=154) were assigned randomly to 1 of 2 treatments. Cows underwent a presynchronization of the estrous cycle composed of an injection of GnRH concurrently with the placement of a progesterone insert, an injection of PGF(2α) and insert removal 7 d later, and a second injection of GnRH 48 h later (study d -16). All cows were then submitted to a hormonal protocol identical to the presynchronization program starting on d 7 of the estrous cycle (study d -9). Cows enrolled in the high progesterone (HP) treatment received no further treatment. Cows in the low progesterone (LP) treatment received additional PGF(2α) injections on study d -14, -13.5, and -13 and again on study d -9, -7, -6.5, and -6. Ovaries were evaluated by ultrasonography, and blood was sampled for concentrations of progesterone and estradiol throughout the study. Uteri were flushed 6 d after artificial insemination (AI) and recovered oocytes-embryos were evaluated. Concentrations of progesterone were less for LP cows from study d -7 to -2; concentrations of estradiol at PGF(2α) and at the last GnRH of synchronization were greater for LP than HP. The proportion of cows in estrus at AI was greater for LP than for HP (38.0 vs. 5.3%). Ovulatory follicles of LP cows had larger diameters at the injections of PGF(2α) (17.2 vs. 14.6mm) and final GnRH (19.4 vs. 16.9%) of the synchronization, which resulted in a larger diameter of the corpus luteum 6 d after AI (24.3 vs. 22.6mm). Double ovulation after the last GnRH of the synchronization was increased in LP (18.6%) compared with HP (4.5%). Fertilization rate was similar and averaged 82.7%. The proportion of embryos and oocytes-embryos classified as grades 1 and 2, proportion of degenerated embryos, and unfertilized-degenerated oocytes-embryos were not different between LP and HP. Number of blastomeres did not differ between LP and HP, but the proportion of live blastomeres tended to be less for LP than HP (94.2 vs. 98.7%). Reducing progesterone concentrations during the synchronization program altered concentrations of estradiol and follicular dynamics, but resulted in similar fertilization and only minor changes in embryo quality.
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 | 0,001 | 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 | 0,000 |
| 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 ».