Effects of starvation and refeeding on growth performace, appetite, GH-IGFs axis levels and digestive function of Acipenser dabryanus.

The aim of this study was to explore the effects and mechanisms of different starvation treatments on the compensatory growth of Acipenser dabryanus. 120 fish (60.532 ± 0.284 g) were randomly assigned to 4 groups (fasting 0, 3, 7or 14 days and then refed for 14 days). During fasting, MBW decreased significantly with prolonged starvation. The whole body and muscle composition, serum biochemical indexes, visceral indexes and digestive enzyme activities had been effected with varying degrees of changes The GH level in serum was significantly increased in 14D; however, IGF-1 showed the opposite trend. The npy mRNA level in brain was significantly improved in 7D, pyy mRNA level in intestine was significantly decreased during fasting. After refeeding, the FBW, PWG, SGR, FI, FE and PER showed no difference between 0D and 3D. The changes of whole body and muscle composition, serum biochemical indexes, visceral indexes and digestive enzyme activities had taken place in varying degrees. GH levels in 3D and 7D were significantly higher than those in the 0D, the IGF-1 content decreased significantly during refeeding. There was no significant difference in npy and pyy mRNA levels. These results indicated that short-term fasting followed by refeeding resulted in full compensation and the physiological and biochemical effects on A. dabryanus were the lowest after three days of starvation and 14 days of refeeding. Additionally, compensation in A. dabryanus may be mediated by appetite genes and growth hormones, and the degree of compensation is also affected by the duration of starvation.