Early posthatch starvation decreases satellite cell proliferation and skeletal muscle growth in chicks

The effect of posthatch starvation on skeletal muscle growth and satellite cell proliferation was examined in chicks. Chicks were either fed or starve d for 48 h posthatch (d 0-d 2, d 2-d 4 or d 4-d 6) and then refed for 41 d. Body and breast muscle weights were significantly lower in starved chicks than in fed controls throughout the experiment. Histochemical staining reve aled that skeletal muscle fiber development in the starved group lagged beh ind that of the fed group. Starvation from d 2 to 4 and d 4 to 6 posthatch had a progressively lesser effect than did immediate posthatch starvation ( P < 0.05). in vitro culturing of breast muscle satellite cells revealed tha t DNA synthesis and number of cells per gram of muscle in the fed chicks pe aked on d 2 and d 3, and then declined. In contrast, DNA synthesis in the c ells of starved chicks declined on d 2 and increased on d 3 when chicks wer e refed. A similar pattern was seen for the number of cells per gram muscle ; however, in general cell numbers tended to be higher in the starved group than in controls (P < 0.1). The results obtained with cultured cells were parallel with in situ immunostaining with 5-bromo-2' -deoxyuridine and prol iferating cell nuclear antigen in breast muscle from experimental chicks, a nd with growth hormone receptor expression. These results suggest that sate llite cell cultures are a reliable tool for evaluating muscle growth in pos tnatal chickens. We conclude that sufficient feed in the immediate postnata l period is critical for satellite cell proliferation and skeletal muscle d evelopment and is thus important for optimal muscle growth.