194 ESTROUS SYNCHRONIZATION AND FIXED-TIME AI IN WOOD BISON (BISON BISON ATHABASCAE)
Notice bibliographique
Résumé
As part of a project involving reproductive biotechnology as a method of preserving Canada’s threatened wood bison population, an experiment was designed to test the effectiveness of steroid-induced ovarian synchronization and fixed-timed AI. The experiment was performed in the early ovulatory season (September) with female wood bison (4 years old, n = 13) and plains bison (2 years old, n = 4, and 8 years old, n = 3). Based on results of a preceding study, progesterone was combined with estradiol as a synchronization treatment to mitigate against untimely ovulation. The bison were blocked by subspecies and assigned randomly to a control group (no treatment; n = 10) or given estradiol 17ß (2.5 mg) + progesterone (50 mg) in canola oil i.m. and a progesterone-releasing intravaginal device (Cue-mate™, Bioniche, Belleville, Ontario, Canada) on Day 0 (n = 10). On Day 8, the Cue-mate™ device was removed and PGF (500 mg Estrumate®, Mallinckrodt Vet GmbH, Friesoythe, Germany) was given to induce luteolysis. On Day 10, all bison were given 5 mg of LH (Lutropin®-V, Bioniche) and artificially inseminated 12 h later with semen collected and frozen previously from wood bison of the same herd. The ovaries were examined daily by transrectal ultrasonography beginning 5 days before treatment and thereafter until the first post-treatment ovulation. Ultrasonographic pregnancy diagnosis was done 30 days post-insemination. No differences were detected between wood and plains bison for any end point, and data were combined for further statistical analyses. Ovarian follicular wave emergence occurred on Day 4.1 ± 0.8 (mean ± SEM) and 4.1 ± 0.3 in the control and treatment groups, respectively (P = 99.3). The interval to new wave emergence was less variable in bison treated with estradiol + progesterone than in untreated controls (residuals, 0.7 ± 0.2 and 1.9 ± 0.5 days, respectively; P < 0.05). The interval from LH administration to ovulation was 2.7 ± 0.6 and 5.4 ± 1.9 days for the treatment and control groups, respectively, and was less variable in the treatment group than in controls (residuals, 1.2 ± 0.4 and 5.3 ± 0.8 days, respectively; P < 0.05). The diameter of the preovulatory follicle was not different between groups and was, on average, 15.2 ± 1.1 mm. Pregnancy was diagnosed in 3 bison in the treatment group and 2 in the control group. In conclusion, treatment with estradiol and progesterone effectively synchronized the interval to wave emergence, and subsequent LH treatment resulted in a synchronous ovulatory response necessary for fixed-time AI in bison. Although the pregnancy rate was modest, perhaps because of issues with semen quality, timing of AI, or quality of the ovulated oocyte, this represents the first report of pregnancy in bison from fixed-time insemination. Supported by grants from the Advancing Canadian Agriculture and Agri-Food Fund, the Agri-Food Innovation Fund, Parks Canada, the World Wildlife Fund, and the Northwest Territories.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 source (Gemma direct ou Codex distillé), 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 ».