The effect of early dietary amino acid levels on muscle satellite cell dynamics in turkeys

Understanding the relationship between nutrition and satellite cell activity will be beneficial in obtaining optimal muscle growth and meat production. The objective of this study was to evaluate the effect of early post-hatch levels of dietary amino acids ± 0.88 NRC, 1.00 NRC, and 1.12 NRC), and feed deprivation on the satellite cell mitotic activity, pectoralis thoracicus muscle weight, and body weight of male turkeys (Meleagris gallopavo). Birds from each treatment were injected with 5-bromo-2′-deoxyuridine (BrdU) to label mitotically active cells. The right pectoralis thoracicus was harvested 1 h after BrdU injection for immunohistochemical and myofiber diameter analysis. On the third day post-hatch, satellite cell mitotic activity was the highest (P < 0.05) in the 0.88 NRC amino acid treatment group and the lowest (P < 0.05) in the feed-deprived group. On the fourth day post-hatch, feed-deprived birds exhibited the lowest (P < 0.05) satellite cell mitotic activity and muscle weight. At 140 days of age, there were no significant differences (P > 0.05) between treatments in body weight or pectoralis thoracicus muscle weight. Research evaluating species-related differences in apoptotic events and in genes regulating cell proliferation may be necessary to devise feeding strategies aimed at obtaining optimal pectoralis thoracicus muscle yield at market age.