The effect of early posthatch nutrition on satellite cell mitotic activity.

Myofiber growth is dependent upon the contribution of new nuclei from the mitotically active satellite cell population. The objective of this study was to examine satellite cell mitotic activity in conjunction with different nutritional paradigms during the early posthatch period. Turkey poults were provided a standard turkey starter diet; the starter diet top-dressed with a hydrated low-fat, highly digestible protein and carbohydrate nutritional hatchling supplement, Oasis; the starter diet top-dressed with Solka-floc dyed green; or no food for the first 3 d posthatch. All birds were fed a standard starter diet during the experimental period. 5-Bromo-2'-deoxyuridine (BrdU) was continuously infused into all treatments (n = 5 all groups) between hatch and 3 d of age. A second group of identically treated poults housed in separate pens (n = 3 to 5) was continuously infused with BrdU between 2 and 9 d of age. Mitotically active satellite cells were identified in the pectoralis thoracicus and quantitated using BrdU immunohistochemistry in combination with computer-based image analysis. Satellite cell mitotic activity was significantly higher (P < or = 0.05) in the birds fed a standard starter diet compared to all other treatments at 3 d posthatch. However, there were no (P > or = 0.05) differences in satellite cell mitotic activity among treatments at 9 d posthatch. The results of the current study suggest that any improvements in meat yield through early nutritional supplementation do not appear to occur through a satellite cell pathway and that there is no compensatory response in the satellite cell population following refeeding after early posthatch starvation.