Effect of physical form of forage on performance, feeding behavior, and digestibility of Holstein calves
Notice bibliographique
Résumé
The physical form of forage may influence rumen development and, consequently, the body weight gain, dry matter (DM) consumption, digestibility, and welfare of dairy calves. The objective of this study was to determine the effect of 2 different physical forms of forage on performance, apparent digestibility, and feeding behavior of young calves. Twenty Holstein male calves (46.8 ± 1.2 kg) were randomly assigned at birth to 1 of 2 feeding treatments in which they were exposed to a mixed ration containing (on a DM basis) 90% crumb starter concentrate and either (1) 10% coarsely chopped (3 to 4 cm) grass hay (CRS; n=10) or (2) 10% finely ground (2mm) grass hay (FN; n=10). All calves were offered 8L/d of milk replacer (MR; 1.2 kg of DM) from birth; the amount of MR was progressively reduced after 5 wk to enable weaning by the end of wk 7. The study finished after wk 8. Consumption of the mixed ration, MR, and water was recorded daily, and calves were weighed twice weekly. Samples of feed and orts were taken in wk 7 and 8 for nutrient content analysis. Behavioral data for each calf were obtained for 2h/d during wk 6 and 8, for a total observation time per animal of 28 h. Total feces were collected during wk 8 to determine apparent digestibility. Calves fed CRS had greater DM intake than those fed FN (2.70 vs. 2.45 ± 0.11 kg/d, respectively) during the week after weaning (wk 8). Body weight gain was similar between treatments; however, calves fed CRS tended to have a greater gain-to-feed ratio than calves fed FN (0.68 vs. 0.63 ± 0.02 kg of gain/kg of DM intake). No differences were observed in crude protein and acid detergent fiber consumption between treatments; however, calves fed CRS tended to consume more neutral detergent fiber than calves fed FN during the last week of the study (719.2 vs. 610.5 ± 25.84 g/d). Calves receiving CRS sorted in favor of neutral detergent fiber to a greater extent than calves consuming FN, whereas calves fed FN sorted in favor of crude protein to a greater extent than calves fed CRS. Apparent DM, crude protein, neutral detergent fiber, and acid detergent fiber digestibility values were greater in calves fed CRS than in those fed FN (72.3, 77.4, 40.7, and 42.7% vs. 69.2, 74.5, 34.0, and 35.6%, respectively). Calves fed FN spent more time performing nonnutritive oral behaviors than those fed CRS, and calves fed FN tended to spend less time idle (either lying or standing) than those fed CRS. In conclusion, providing chopped hay to young calves improved feed intake, DM, crude protein, neutral detergent fiber, and acid detergent fiber digestibility values during the week after weaning, and reduced nonnutritive oral behaviors compared with offering ground hay.
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 | 0,000 | 0,001 |
| 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) | 0,001 | 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 ».