This study was carried out to assess the Cobb broiler productive traits and the expression of energy metabolism (avANT, ATP5G1 and ATP5E) and mitochondrial biogenesis-related genes (PPARγ and avPGC-1α). Also, the expression of some growth-related genes (MyoD, MyoG and MSTN) in breast muscle during pre-hatch and post hatch. The pre-hatching stage on days 12, 15, and 19 and the post-hatching stage on days 21 and 35. The birds were individually weighted at 0, 7, 14, 21, 28, and 35 days. The growth performance indices like the TBWG, FC, FE, and FCR, weekly feed consumption and total feed intake were evaluated. Different expression levels of avANT and avPGC-1α genes at the different embryonic stages were observed. The expression level of ATP5G1, ATP5E, and PPARγ were not detected at pre-hatch. Meanwhile, ATP5G1 was higher in small body weight unlike ATP5E that was significantly lower in small BW birds. avPGC-1α and PPARγ on 21^st day showed significant up-regulation in small BW, while at 35^th day, no significant difference in their expression in small and large BW broilers. Little expression of growth-related genes was observed at pre-hatch. At post-hatch, MyoD was higher in large BW compared to small BW broilers. MSTN was up-regulated in small BW compared to large one. We concluded that the avANT, PGC-1α, and MyoD genes have major role at pre-hatch and post hatch-till 21th day. However, MyoG, ATPG1, and ATP5E play strong roles in skeletal muscle growth at the marketing age which could be useful for the genetic improvement in broiler.