103 INFLUENCE OF ESTRUS EXPRESSION AND TREATMENT WITH GONADOTROPIN-RELEASING HORMONE ON PREGNANCY RATES IN RECIPIENTS SYNCHRONIZED WITH PROGESTERONE DEVICES AND ESTRADIOL AND TRANSFERRED AT A FIXED TIME
Notice bibliographique
Résumé
An experiment was designed to evaluate whether expression of oestrus in recipients synchronized with progesterone devices and oestradiol affects pregnancy rates to a fixed-time embryo transfer (FTET). A secondary objective was to determine whether administration of gonadotropin-releasing hormone (GnRH) to those recipients not showing oestrus by 48 h after device removal had an effect on pregnancy rates. Mature, non-lactating beef recipients (Bonsmara, Brangus, and Braford; n = 729), with a corpus luteum (CL) or a follicle =8 mm in diameter detected by ultrasonography (Mindray DP 30, Shenzhen, China) and body condition score 2 to 4 (1 to 5 scale) were synchronized in 7 replicates. On Day 0, recipients received a progesterone device (DIB 0.5 g, Zoetis, Buenos Aires, Argentina) and 2 mg of oestradiol benzoate (Gonadiol, Zoetis). On Day 8, DIB were removed and recipients received 400 IU eCG (Novormon 5000, Zoetis) plus 0.5 mg of oestradiol cypionate (Cipiosyn, Zoetis) and 500 µg of cloprostenol (Cyclase, Zoetis). In addition, all cows were tail-painted on the sacrococcygeal area (CeloTest, Biotay, Buenos Aires, Argentina) at DIB removal and were observed to determine the expression of oestrus, according to the percentage of paint loss 48 h later. The animals that showed oestrus (paint loss >30%) were recorded, and those with paint loss =30% (not in oestrus) were randomly allocated to receive 100 µg of gonadorelin (GnRH; Gonasyn, Zoetis) or no treatment. On Day 17, all recipients were examined by ultrasonography and those with a CL =18 mm (G1), =16 and <18 mm (G2), or =14 and <16 mm (G3) in diameter received in vivo-produced frozen-thawed embryos by direct transfer or fresh in vitro-produced embryos. Pregnancy was diagnosed by ultrasonography at 23 days after FTET, and data were analysed by logistic regression. There were no differences between replicates, in vivo- and in vitro-produced embryos, or operators (P > 0.2). However, the proportion of recipients transferred and pregnant (P/FTET) was higher (P < 0.05) for those that showed oestrus at 48 h after DIB removal (422/454, 93.0% and 227/471, 48.2%) than those that did not show oestrus (109/211, 51.7% and 45/120, 37.5%). Within the recipients not showing oestrus, P/FTET was significantly higher (P < 0.05) in those that received GnRH (34/74, 45.9%) than in those that did not receive GnRH (12/46, 26.1%). There was a significant interaction (P < 0.05) between CL diameter and expression of oestrus. When recipients had CL =18 mm in diameter (G1), P/FTET did not differ (oestrus: 164/338, 48.5% v. no oestrus 30/65, 46.2%); however, when CL diameter was <18 mm and =14 mm (G2 and G3), P/FTET was higher (P < 0.05) in those that showed oestrus (37/85, 43.5%) than in those that did not show oestrus (11/43, 25.6%). Finally, P/FTET was higher (P < 0.05) in recipients with a CL (268/573, 46.8%) on Day 0 than in those with follicles >8 mm in diameter (4/18, 22.2%). In conclusion, the expression of oestrus significantly affected the percentage of recipients selected for embryo transfer and P/FTET. Furthermore, treatment of recipients not showing oestrus by 48 h after DIB removal with GnRH at that time increased P/FTET.
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 | 0,000 | 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 ».