Abstract：Abstract The grass carp (Ctenopharyngodon idellus) growth hormone gene transgenic common carp (Cyprinus carpio) is a new variety of fish which aims to enhance growth. However, transgenisis may alter the response of the transgenic carp to different environmental conditions. To examine the effect of feeding rations on energy allocation and overwinter of fast growth transgenic common carp, a growth and overwinter trial on transgenic and nontransgenic carp was conducted under 2 feeding rations (satiation and half-satiation). At the growth trial in summer and autumn, the growth rate of body weight of satiation transgenic (ST) fish was 1.33 times faster than that of satiation nontransgenic (SN) fish, and half-satiation transgenic (HT) fish was 1.51 times faster than half-satiation nontransgenic (HN) fish. However, no significant difference was found between HT and SN in the growth rate of body weight. The moisture content of HN, SN, HT and ST in turn significantly reduced. There was no significant difference in protein content within genotype, but the protein content of ST was significantly higher than that of SN. The lipid content and energy content of HN, SN, HT and ST were increased significantly by degrees. The transgenic carp did not reduce satiation ration in late autumn while the nontransgenic carp did. There were no significant difference in overwinter survival rate among treatments, and feeding history only affected the energy content after overwinter. Our study indicated that the energy allocation in response to feeding ration and overwinter was consistent between transgenic and nontransgenic carp. The transgenic carp would assign more energy to growth, but less energy to storage under food restriction. There was no significant difference in overwinter ability among transgenic and nontransgenic carp. The present study may provide reference for ecological safety assessment of transgenic carp.
