190 Impact of post-weaning feeding management during the growing phase on growth performance of Holstein steers, and beef × Holstein steers and heifers.
Notice bibliographique
Résumé
Abstract Feed intake, growth, carcass characteristics, and time to finish are expected to differ between Holstein and beef × Holstein cattle. However, the effects of dietary strategy on these outcomes are not well established. This study compared the effects of dietary energy density during the growing phase (until body weight [BW] = 350 kg) on dry matter intake [DMI] and efficiency, growth, average daily gain [ADG], hip height, body length, and days on feed [DOF] of Holstein steers, beef × Holstein (B×H) steers, and B×H heifers. One hundred and nineteen individually housed calves (n = 40 Holstein steers, 40 B×H steers, 39 B×H heifers) were used in a randomized complete block design with a 3 × 2 factorial structure. After a 15-d receiving phase, calves were paired by initial BW (205 ± 23 kg) and randomly assigned to either a rapid growth (RG; 1.9 kg/d) or moderate growth (MG: 1.2 kg/d) program. To target RG, calves received a diet containing 48% starch and 15% crude protein [CP], while MG calves received a diet containing 28% starch and 15% CP. Feed intake was recorded weekly through collection of orts and adjusted for dry matter, while BW, hip height, and body length were measured every 28-d. Data were analyzed using the mixed model procedure of SAS with the fixed effects of program, breed/sex, and the 2-way interaction, with initial BW as a covariate. The total DOF until 70% of each treatment reached 350 kg BW was 78-d, 91-d, 104-d, 91-d, 113-d, and 113-d for RG B×H steers, RG B×H heifers, RG Holstein steers, MG B×H steers, MG B×H heifers, and MG Holstein steers, respectively. A breed/sex × program interaction was observed for DMI, such that the average DMI (10.2 kg/d) for the MG B×H steers during the growth phase was 23 to 30% greater than all other treatments (P < 0.01). However, the increased DMI did not result in improved ADG; rather, RG B×H steers grew 15 to 24% faster than all other treatments (Breed/sex × program, P = 0.03). The RG B×H steers had the greatest gain to feed ratio (G:F; 0.233 kg/kg), while MG B×H steers had the lowest (0.165 kg/kg). During the growing phase, hip heights were higher (P < 0.01) for Holstein and B×H steers compared to B×H heifers regardless of feeding program; while body lengths were shortest for RG B×H steers and longest for RG Holstein steers (Breed/sex × program, P < 0.01). Overall, feeding a high-energy diet (RG program) reduced DOF during the growth phase; however, further evaluation of performance in the finishing period is required. Crossbred steers had greater feed efficiency than Holstein steers, while crossbred heifers were similar to both groups of steers.
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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) | 0,000 | 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 ».