225 ADDITION OF EQUINE CHORIONIC GONADOTROPIN TO A TRADITIONAL FOLLICLE STIMULATING HORMONE PROTOCOL FOR SUPEROVULATION OF BOS TAURUS BEEF COWS
Notice bibliographique
Résumé
This study examined the superovulatory responses of Bos taurus beef cows maintained in a commercial embryo transfer facility. Donors were superovulated 1 to 3 times each with either a traditional 8 injection FSH protocol (controls, n = 126) or 6 injections of FSH with the seventh or eighth FSH treatments replaced by 2 injections of eCG (treatment, n = 134). During the 5-month study, 132 donors were alternatively assigned to a control or treatment group for a single superovulation and an additional 62 animals were superovulated 2 (n = 58) or 3 times (n = 4) in a crossover design. Although 14 beef breeds were represented in the study, 87% of the cows were Angus, Red Angus, Polled Hereford, or Charolais. All donors were synchronized on Day 0 with a CIDR, 5 mg of oestradiol-17ß and 100 mg of progesterone. Starting on Day 4 (p.m.), controls were injected twice daily for 4 days with descending doses of porcine FSH (Folltropin-V®, Bioniche Animal Health, Belleville, Ontario, Canada). Cows received 750 µg of cloprostenol (Estrumate®, Intervet Schering-Plough, Summit, NJ, USA) at the seventh FSH injection and the CIDR was removed at the eighth FSH injection. Based on previous experience with specific, individual animals, total FSH dose per donor ranged from 240 to 400 mg. However, 74% of treatments involved 380 mg for controls and 310 mg for treated donors that received eCG. In addition, donors that were superovulated more than once received the same FSH dose in the crossover, treatment-control design. In the treatment group, 200 IU of eCG (Pregnecol™ 6000, Bioniche Animal Health) was substituted for the seventh and eighth FSH injections. Inseminations were conducted on a timed AI basis, with one unit of semen 32 h and a second 48 h following CIDR removal. Results were analysed by ANOVA as shown in Table 1. Although more ova/embryos and unfertilized ova (UFO) were recovered in the control group, the control and treatment groups did not differ in the number of grade 1, 2, or 3 embryos or in the number of degenerate embryos. Previous superovulation studies in South America using eCG to replace the last 2 injections of FSH resulted in more total ova/embryos in Nelore cows but not heifers and in more embryos in Brangus and Sindhi cows. The mean embryo production for the control cows in this study was high and the addition of eCG in the protocol did not improve embryo production. Failure of eCG to increase the number of embryos for Bos taurus cows in this study compared with previous studies may be due to differences with Bos taurus versus Bos indicus breeds or differences in management factors between Canada and South America. The high response rate in the controls may also have contributed to the failure of any advantage of adding eCG to the treatment protocol. Table 1. Mean numbers (± SEM) of ova and embryos recovered from Bos taurus females superovulated with 2 different protocols
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) | 0,000 | 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) | 0,002 | 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 ».