183 EFFECTS OF LONG-TERM NUTRITIONAL RESTRICTION ON PREOVULATORY LUTEINIZING HORMONE SURGE, LEPTIN, AND LUTEAL PHASE IN LLAMAS (LAMA GLAMA)
Notice bibliographique
Résumé
The aim of the study was to determine the effect of long-term energy restriction on preovulatory LH surge and luteal phase in llamas. Mature nonlactating, nonpregnant, female llamas (n = 16) were assigned randomly to the following groups: (1) llamas received Ballica sp. hay ad libitum and 300 g d–1 of commercial concentrate (control group, n = 8, BCS = 3.9) or (2) llamas were fed the same feed but the amount was progressively reduced from 70% to 40% of their maintenance energy requirement (MER) for a period of 87 days, until the final BCS was 2.5 (restricted group, n = 8). After 2 months and 21 days of 40% MER diet, ovarian follicular wave emergence was synchronized by transvaginal ultrasound-guided ablation of follicles =5 mm in diameter using a 17-ga needle attached to a 5-MHz convex-array transducer. Ten days after follicle ablation (Day 0), llamas were given an i.m. dose of 50 µg of gonadorelin acetate to induce ovulation. Frequent blood samples were taken every 30 min for 6 h and every 15 min for 1 h for plasma LH and leptin concentration measurements, respectively, immediately after treatment. Llamas were examined daily by transrectal ultrasonography for 20 days to record serial changes in the CL diameter. In addition, blood samples were taken every 2 days from Day 0 to 16 to determine plasma concentrations of leptin and progesterone. Discrete dependent variables were compared between groups by Student t-tests and continuous dependent variables were analysed by analyses of variance with repeated-measures. There was an effect of time on plasma LH concentration (P = 0.001), but not an effect of group (P = 0.1) or interaction (P = 0.6) after gonadorelin acetate treatment. Plasma leptin concentration was lower in llamas from the restricted than that of the control group after gonadorelin treatment [effect of time, group (P = 0.01), and interaction (P = 0.01)]. The maximum diameter of the CL and plasma progesterone concentration were lower in the restricted than in the control group, and both variables were affected by group (P = 0.01, P = 0.02), and day (P = 0.001, P = 0.001, respectively). Plasma leptin concentration was lower in the restricted than that of the control group during the entire experiment. In conclusion, long-term nutritional restriction affected negatively CL diameter, progesterone secretion, and leptin plasma concentration in llamas. The differential response of leptin to gonadorelin acetate treatment could reflect a subfertlity-nutritional induced problem related with steroidogenesis, oocyte quality, ovulation, and early embryo development processes. Research supported by Postdoctoral Fondecyt N° 3110095.
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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 ».