97 IN VIVO AND IN VITRO EMBRYO PRODUCTION WITH Y-SEXED SORTED OR CONVENTIONAL SEMEN IN BEEF CATTLE
Notice bibliographique
Résumé
An experiment was designed to evaluate in vivo and in vitro embryo production following the use of frozen–thawed conventional or Y-sexed semen from a Brangus bull with known high fertility. For in vivo embryo production, Brangus heifers (n = 12) were superovulated twice in a crossover design and inseminated with sexed or conventional semen. On Day 0, all heifers received an intravaginal progesterone device (DIB 1 g, Syntex S.A., Buenos Aires, Argentina) and 2.5 mg oestradiol benzoate and 50 mg progesterone (Progestar, Syntex S.A.) by intramuscular injection (IM). On Day 4, heifers were superstimulated with 200 mg of NIH-FSH-P1 Folltropin-V (Bioniche Animal Health, Belleville, Ontario, Canada) in twice-daily decreasing doses over 4 days. In the a.m. and p.m. of Day 6, all heifers received PGF2a (Ciclase, Syntex) and DIBs were removed in the p.m.. In the a.m. of Day 8, heifers received 100 µg de Gonadolerin (Gonasyn, Syntex S.A.) and were randomly allocated to receive either one straw of conventional semen (24 × 106 sperm per dose) 12 and 24 h later or two straws of sexed semen (2.4 × 106 sperm per dose) 18 and 24 h after GnRH. Ova/embryos were collected nonsurgically on Day 15 and evaluated following IETS recommendations. Means were compared by t-test. Mean ( ± s.e.m.) number of ova/embryos, fertilized ova, and transferable embryos were 14.8 ± 2.7, 9.4 ± 1.8, and 7.1 ± 1.7 v. 16.8 ± 3.1, 9.9 ± 2.5, and 8.1 ± 2.0 for donors inseminated with conventional or sexed semen, respectively (P > 0.6). For in vitro production, oocytes were obtained from 50 ultrasound-guided follicle aspiration (OPU) sessions that was performed at random stages of the oestrous cycle and without superstimulation in 22 Brangus cows and heifers. Oocytes were classified and matured in TCM-199 medium with NaHCO3 and supplemented with 1% fetal bovine serum. Semen samples from the same bull used for in vivo embryo production were selected using Percoll and capacitated in Fert medium and used at a final concentration of sperm/mL for nonsexed semen and 2 × 106 sperm mL–1 for sexed semen. After 16 h (sexed) or 18 h (conventional) in Fert medium, zygotes were denuded and cultured in SOF supplemented with 0.4% BSA under oil at 37°C, 5% CO2 and saturated humidity for 7 days. The total number of oocytes matured and fertilized was 528 and 318 for conventional and sexed semen, respectively. Means were compared by t-test and proportions by chi-squared test. Mean (± s.e.m.) number of cleaved zygotes and blastocysts produced per OPU session did not differ between conventional (11.0 ± 1.4 and 7.1 ± 1.0) and sexed (8.7 ± 0.8 and 4.9 ± 0.7; P > 0.2) semen. However, the proportion of cleaved zygotes and blastocysts produced were significantly higher (P < 0.05) with conventional semen (61.2%; 329/538 and 39.4%; 212/538) than with sexed semen (54.4%; 173/318 and 30.8%; 98/318), respectively. In conclusion, comparable number of embryos can be obtained in vivo with sexed or conventional semen from a bull with proven high fertility. However, the proportion of blastocysts produced in vitro is likely to be reduced following the use of sexed as compared with conventional semen from the same bull.
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 | 0,000 |
| 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 ».