290 Vitamin A and Beta-Carotene Supplementation on Growth Performance, Immune System, and Mammary Gland Development in Finishing Pigs
Notice bibliographique
Résumé
Abstract A total of 224 finishing pigs were randomly assigned to split-sex pens (n = 4 pigs per pen). Each pen was assigned to one of four diets: control (7,656 IU vitamin A/kg), control diet supplemented with vitamin A (4.36 ppm; Rovimix A 1000, DSM, NJ, US), control diet supplemented with beta-carotene (163.28 ppm; Rovimix β-Carotene 10%, DSM, NJ, US), or control supplemented with oxidized beta-carotene (40 ppm; 10% active ingredient, Avivagen, Ottawa, ON, Canada). Pigs and feeder weights were recorded at the start of the study (d 0) and end of each phase (days 21, 42, and 63). A subset of gilts was randomly selected and a blood sample for vitamin A (retinol) analysis was collected on days 0, 18, 39, 60, and 63. The same gilts were vaccinated against Lawsonia intracellularis and porcine circovirus. Antibodies against each vaccination were measured on days 18, 39, and 60. At the end of the study, the subset of gilts was euthanized to obtain a liver sample for vitamin A (retinyl palmitate is converted to retinol for measurement) analysis and a jejunum sample to measure the mRNA abundance of genes involved in vitamin A metabolism (alcohol dehydrogenase class 1, lecithin retinol acyltransferase phosphatidylcholine-retinol O-acyltransferase, retinol binding protein, and beta-carotene oxygenase 1). Mammary tissue from the second and fourth right anterior mammary glands were collected to assess gland development via immunohistochemical staining for T cells, B cells, and macrophages (CD3, CD20, and IBA1, respectively) and DNA extraction. Vaccine antibodies measures, vitamin A analysis, and mammary immunohistochemical staining was completed at Iowa State University Veterinarian Diagnostic Laboratory (Ames, IA). Data were analyzed in SAS 9.4 (Statistical Analysis System, Cary, NC) via GLIMMIX procedure. Pen was the experimental unit and fixed effects were diet and time. Gilts were nested within pen when appropriate to account for more than one gilt per pen. Oxidized beta-carotene supplementation increased (P = 0.02) average daily gain across phases; however, there were no differences (P = 0.18) in the body weight of pigs. There was no effect (P > 0.05) of diet on plasma or hepatic retinol, IgG or IgM concentrations, immune cell presence, or DNA in mammary tissue. Supplemented vitamin A tended (P = 0.05) to increase the expression of retinol binding protein in the jejunum, but other genes were not affected (P > 0.05) by dietary treatments. A diet by time interaction (P = 0.04) was noted for circovirus sample-to-positive ratios and titer levels, where vitamin A supplementation had better vaccine responses at the end of the study. Thus, pigs supplemented with oxidized beta-carotene had an improved average daily gain over vitamin A supplemented pigs, but pigs supplemented with vitamin A appeared to have a more robust immune system.
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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 ».