445 Effects of feed restriction on growth, blood chemistry and reproductive performance in replacement gilts
Notice bibliographique
Résumé
Abstract The practical application of embryo transfer in pigs could benefit from using embryo donors for multiple cycles. Thus, raising the need to investigate feeding strategies for donors which will not be required to recover body condition lost during previous lactation. The objective was to evaluate the effects of temporary feed restriction, from d 6 to 14 of the estrous cycle, on growth, blood variables and reproductive performance in replacement gilts. Replacement gilts (n = 20; TN70, Topigs Norsvin, Oak Bluff, Canada) were assigned equally across 2 feeding regimens following a randomized complete block design where the block was backfat thickness. The feeding regimens were based on the first day of the estrous cycle: CON, recommended feeding levels from d 0 to 14 and a flush feeding (25% above recommended levels) from d 15 until d 21; or RES, CON but with restricted feeding (25% below recommended levels) from d 6 to 14. The CON treatment was based on the recommendations of the Feed Manual TN70 (Topigs Norsvin, 2015). On d 0, 5, 14 and 20 of the cycle, body weight and backfat thickness were measured. On d 21 (detected estrus), gilts were inseminated and on d 27 they were euthanized to collect embryos, ovaries and uterus. The uterus and ovaries were weighed whereas corpora lutea were counted and weighed. Blood serum was collected on d 14, and 20 for chemical analyses. Data were analyzed using the mixed procedure of SAS where each gilt was the experimental unit. Feeding regimens were considered as the fixed effect and backfat block as the random effect. Means were obtained with the LSMEANS statement. No differences (P > 0.05) were observed on growth performance among feeding regimens. However, when comparing the average daily gain (ADG) within feeding regimens between feeding periods, no differences (P > 0.05) were observed among gilts fed CON whereas gilts fed RES showed a decreased (P < 0.05) ADG during d 6 to 14 compared with d 0 to 5 and d 15 to 21. Regarding blood serum variables, gilts fed RES had greater (P < 0.05) total protein and potassium but less (P < 0.05) sodium-to-potassium ratio than gilts fed CON on d 14. On d 20, Gilts fed RES had greater (P < 0.05) cholesterol values than gilts fed CON. No differences (P > 0.05) were observed on the number of corpora lutea, number of embryos collected or on collection efficiency. Similarly, no differences (P > 0.05) were observed on the weight of reproductive organs or on measurements of ovaries among feeding regimens. In conclusion, restricting feed intake of replacement gilts by 25% of the recommendation from d 6 to 14 of the estrous cycle reduced ADG without compromising their reproductive performance.
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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) | 0,001 | 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 | 0,001 |
| 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 ».