Growth-promoting effects of sustained swimming in fingerlings of gilthead sea bream (Sparus aurata L.).
Fish growth is strongly influenced by environmental and nutritional factors and changing culture conditions can help optimize it. The importance of early-life experience on the muscle phenotype later in life is well known. Here, we study the effects of 5 weeks of moderate and sustained swimming activity (5 BL s(-1)) in gilthead sea bream during early development. We analysed growth and body indexes, plasma IGF-I and GH levels, feed conversion, composition [proximate and isotopic ((15)N/(13)C)] and metabolic key enzymes (COX, CS, LDH, HOAD, HK, ALAT, ASAT) of white muscle. Moderate and continuous exercise in fingerlings of gilthead sea bream increased plasma IGF-I, whereas it reduced plasma GH. Under these conditions, growth rate improved without any modification to feed intake through an increase in muscle mass and a reduction in mesenteric fat deposits. There were no changes in the content and turnover of muscle proteins and lipid reserves. Glycogen stores were maintained, but glycogen turnover was higher in white muscle of exercised fish. A lower LDH/CS ratio demonstrated an improvement in the aerobic capacity of white muscle, while a reduction in the COX/CS ratio possibly indicated a functional adaptation of mitochondria to adjust to the tissue-specific energy demand and metabolic fuel availability in exercised fish. We discuss the synergistic effects of dietary nutrients and sustained exercise on the different mitochondrial responses.
['Blasco|Josefina|J|', 'Moya|A|A|', 'Millán-Cubillo|A|A|', 'Vélez|E J|EJ|', 'Capilla|E|E|', 'Pérez-Sánchez|J|J|', 'Gutiérrez|J|J|', 'Fernández-Borrás|J|J|']
D000367:Age Factors D000821:Animal Feed D000818:Animals D004734:Energy Metabolism D013006:Growth Hormone D007334:Insulin-Like Growth Factor I D008931:Mitochondria, Muscle D024510:Muscle Development D018482:Muscle, Skeletal D009752:Nutritional Status D010641:Phenotype D021541:Sea Bream D013550:Swimming
White muscle Exercise COX/CS IGF-I/GH RNA/DNA δ13C/δ15N