Enhanced mitochondrial complex gene function and reduced liver size may mediate improved feed efficiency of beef cattle during compensatory growth.
Funct Integr Genomics
; 10(1): 39-51, 2010 Mar.
Article
in En
| MEDLINE
| ID: mdl-19777276
ABSTRACT
Growing ruminants under extended dietary restriction exhibit compensatory growth upon ad libitum feeding, which is associated with increased feed efficiency, lower basal energy requirements, and changes in circulating concentrations of metabolic hormones. To identify mechanisms contributing to these physiological changes, 8-month-old steers were fed either ad libitum (control; n = 6) or 60-70% of intake of control animals (feed-restricted; n = 6) for a period of 12 weeks. All steers were fed ad libitum for the remaining 8 weeks of experimentation (realimentation). Liver was biopsied at days -14, +1, and +14 relative to realimentation for gene expression analysis by microarray hybridization. During early realimentation, feed-restricted steers exhibited greater rates of gain and feed efficiency than controls and an increase in expression of genes functioning in cellular metabolism, cholesterol biosynthesis, oxidative phosphorylation, glycolysis, and gluconeogenesis. Gene expression changes during feed restriction were similar to those reported in mice, indicating similar effects of caloric restriction across species. Based on expression of genes involved in cell division and growth and upregulation of genes encoding mitochondrial complex proteins in early realimentation, it was concluded that reduced hepatic size and increased mitochondrial function may contribute to improved feed efficiency observed during compensatory growth.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cattle
/
Electron Transport Chain Complex Proteins
/
Feeding Behavior
/
Liver
/
Meat
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Funct Integr Genomics
Journal subject:
BIOLOGIA MOLECULAR
/
GENETICA
Year:
2010
Document type:
Article
Affiliation country:
Estados Unidos