Effects of cyclical short-term food deprivation and refeeding on compensatory growth and gene expression of SOD, GPX and HSP70 in Schizothorax wangchiachii.

The present study evaluated the effects of cyclical short-term food deprivation and refeeding on growth performance, body composition, and gene expression of SOD, GPX and HSP70 in Schizothorax wangchiachii.The experimental design included four feeding protocols for eight weeks: feeding every day of the week (control), starvation for one day and refeeding for six days per week (S1F6 treatment), starvation for two days and refeeding for five days per week (S2F5 treatment), and starvation for three days and refeeding for four days per week (S3F4 treatment). The results showed that no significant difference in final body weight, specific growth rate and feed conversion efficiency were observed among the treatments (P > 0.05).The feeding rate significantly increased with the duration of food deprivation per week compared to the control (P < 0.05). The expression levels of HSP70 showed no significant differences in the gill, liver and spleen of S.wangchiachii subjected to different feed restriction regimes(P > 0.05), but in the kidney, the expression levels of HSP70 were significantly downregulated in S1F6 and S2F5 compared to the control(P < 0.05). The expression levels of SOD and GPX in the examined tissues were not affected by the different feed restriction regimes(P > 0.05). In conclusion, full compensatory growth was observed in S.wangchiachii under eight cycles of food deprivation and refeeding. Hyperphagia was the main mechanism of compensatory growth of S.wangchiachii.