PSVI-7 Effects of increasing levels of calcium on nursery pig growth performance and health
Notice bibliographique
Résumé
Abstract The objective of this experiment was to determine the optimal level of total calcium (Ca) to maximize growth performance and health during the nursery period. In total, 2,473 weaned pigs (7.77 ± 2.89 kg initial body weight, 21 days old) were housed in 3 barns and allotted to 29 pens per treatment with 20-22 mixed sex pigs per pen. Experimental diets were formulated to test four levels of total Ca (0.47, 0.52, 0.57, and 0.62%) by adding calcium carbonate at the expense of corn. All experimental diets contained equal amount of total P (0.59 and 0.61%, phase 1 and 2, respectively) and 1,100 FTU/kg of microbial phytase. The experiment lasted for 43 days, and pigs were fed with experimental diets during the first two nursery phases (21 days) and received a common diet during phase 3 (22 days). All diets contained feed medication, whereas water medication and individual parenteral medications were allowed as needed and recorded. Pig and feed weights were recorded at the beginning and end of each phase, and pen scouring (yes/no) was assessed on day 3, 6, 17, and 23. All data were analyzed in R using procedures provided by the lme4, lmerTest and forestinventory packages. Performance variables were analyzed as a general linear model. Mortality, removals, injectable treatments, and scouring were analyzed as a probabilistic generalized mixed model specifying a binomial distribution with a logit link with treatment as fixed effect and location block and barn as random effect. Contrast statements were used to determine linear and quadratic effect of increased dietary inclusion of Ca. During this trial, pigs had Streptococcus suis and Escherichia coli challenges particularly during phase 3, leading to high closeout mortalities (7-10%). Results indicated that under these conditions, increasing dietary total Ca from 0.47 to 0.62% did not have an effect on growth performance (average daily feed intake, average daily gain, final body weight, and feed efficiency) for each phase and overall period (Table 1). No differences in probability of injectable treatments and probability of pen scouring were observed among treatments. However, probability of mortality and removals tended to linearly increase (P = 0.07) during phase 1 and 2 and numerically increased during the overall period as total Ca in diets increased. In conclusion, increasing levels of Ca from 0.47 to 0.62% did not affect growth performance, however, it numerically increased the probability of mortality and removals under Strep and E. coli challenge conditions.
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 | 0,001 | 0,001 |
| 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 | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 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 ».