The impact of low-nutrient and conventional diets on lameness, tibial dimensions and tibia ash concentrations for two fast-growing genotypes of broiler chickens
Notice bibliographique
Résumé
Lameness is a critical welfare issue for the broiler industry, with fast growth being a causal factor.Diets may play an important role in both growth rates and lameness.Therefore, this study evaluated the impact of 2 diets (low-nutrient and conventional diet) on lameness, tibial dimensions, weight, ash concentration, and body weight (BW) in 2 commercial lines of broiler chickens.A total of 624 mixed sex birds from 2 fast-growing strains (A and B) of broiler chickens were placed in 24 pens (26 birds/pen; 23.23 kg bird/m2) and fed either a conventional (CV) or a low nutrient (LN) diet (n = 156).The LN diet had approximately 2% lower CP level compared with the CV diet throughout the trial.From each pen, 12 birds were wing-banded and followed from hatch.Individual BW was determined biweekly.On d 28, 4 wing-banded birds/pen (sentinel birds, n = 96) were chosen based on BW.On d 42, a latency to lie test (a validated method to assess lameness in broiler chickens, with lameness being associated with a reduced latency to lie in shallow water) was performed on sentinel birds.Birds were slaughtered on d 46 (BW = 3.22 0.076 kg) and both right and left tibia from sentinel birds were removed to determine tibial length, diameter, and tibial fresh weight (total and relative to BW).Bone ash concentration (%) was measured in the left tibia to estimate bone mineralization and composition.Data were analyzed as a complete randomized design with a 2 2 factorial arrangement with strains (A and B) and diets (LN and CV) as main factors and with final BW as a covariate, using Proc Glimmix in SAS.No interactions between diet and strain were observed for any parameter evaluated (P > 0.05).There was an effect of strain on BW at d 14 (P < 0.0001), d 28 (P < 0.0001) and d 42 (P < 0.0001), with heavier BW observed in strain A compared with strain B (248 g difference at d 42).Diet only affected BW at d 42 (P = 0.01).Birds fed CV diet were 119 g heavier than birds fed the LN diet.Latency to lie was not affected by diet (P = 0.84) or strain (P = 0.40).Tibial length was not affected by strain (P = 0.08) or diet (P = 0.09).However, birds fed the CV diet had a greater tibia diameter compared with the LN diet (P = 0.04).Consistently, tibial fresh weight (P = 0.02) and tibial fresh weight:BW ratio (P = 0.01) were greater for the CV-fed group.Tibial ash concentrations were not affected by strain (P = 0.43) or diet (P = 0.52).Strain influenced BW, but did not affect tibial morphology or lameness.Diet density affected BW at d 42, tibial diameter and weight, but not lameness.Further studies should investigate if slower growing strains of broilers have improved leg health and welfare.
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 | 0,000 | 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 | 0,001 |
| 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 ».