Association between residual feed intake, digestion, ingestive behavior, enteric methane emission and nitrogen metabolism in Nellore beef cattle.
Anim Sci J
; 91(1): e13455, 2020.
Article
de En
| MEDLINE
| ID: mdl-33025683
ABSTRACT
This study aimed to evaluate nutrient intake and digestibility, enteric methane emission and nitrogen utilization efficiency in Nellore cattle ranked by residual feed intake (RFI). Twenty-four Nellore bulls at 466 ± 24 days of age and with 352 ± 14.6 kg of body weight, classified as low and high RFI, were evaluated. Animals were kept in individual pens for three periods of 28 days and variables were measured. Data were analyzed as repeated measures over time, considering as fixed effects RFI class, period and RFI class x period interaction, and linear (co)variate of age. No significant differences in dry matter or nutrient intake were detected between RFI classes, but total digestible nutrients intake tended to be lower in low RFI animals, and apparent nutrient digestibility was higher in high RFI animals. Partial efficiency of growth tended to be lower in high RFI animals. RFI class did not interfere with enteric methane production or microbial protein synthesis, but fecal nitrogen output was higher in low RFI animals. The greater efficiency of low RFI animals is consequence of lower maintenance requirements, since energy from higher nutrients digestibility in high RFI animals was spent on metabolic processes other than body tissue deposition.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Comportement animal
/
Bovins
/
Tube digestif
/
Régime alimentaire
/
Digestion
/
Consommation alimentaire
/
Gaz à effet de serre
/
Comportement alimentaire
/
Phénomènes physiologiques nutritionnels chez l'animal
/
Méthane
Type d'étude:
Prognostic_studies
/
Risk_factors_studies
Limites:
Animals
Langue:
En
Journal:
Anim Sci J
Sujet du journal:
MEDICINA VETERINARIA
Année:
2020
Type de document:
Article
Pays d'affiliation:
Brésil