Vitamin A injection at birth improves muscle growth in lambs

Abstract

Vitamin A and its metabolite, retinoic acid (RA) play important roles in regulating skeletal muscle development. This study was conducted to investigate the effects of early intramuscular vitamin A injection on the muscle growth of lambs. A total of 16 newborn lambs were given weekly intramuscular injections of corn oil (control group, n = 8) or 7,500 IU vitamin A palmitate (vitamin A group, n = 8) from birth to 3 wk of age (4 shots in total). At 3 wk of age and weaning, biceps femoris muscle samples were taken to analyze the effects of vitamin A on the myogenic capacity of skeletal muscle cells. All lambs were slaughtered at 8 months of age. The results suggest that vitamin A treatment accelerated the growth rate of lambs and increased the loin eye area (P 0.05). Moreover, vitamin A upregulated the expression of PAX7 (P 0.05) as evidenced by myogenic gene expression and fusion index. Taken together, neonatal intramuscular vitamin A injection promotes lamb muscle growth by promoting the myogenic potential of satellite cells.

Keywords

• Vitamin A
• Lamb
• Muscle
• Retinoic acid
• Myogenesis
• Satellite cell