Effect of cyclical feeding on compensatory growth, nitrogen and phosphorus budgets in juvenile L itopenaeus vannamei

This study assessed the effect of cyclical feeding on compensatory growth, nitrogen (N) and phosphorus (P) budgets of juvenile L itopenaeus vannamei . A 36‐day growth trial was performed with four different feeding protocols. The control group (S0) was fed to satiation twice every day during the whole experimental period; treatment groups S1, S2 and S3 were fed by the 9, 5 and 3 cycles of 1:3, 2:5 and 3:9 (fasting days:feeding days) respectively. Fasting in S1, S2 and S3 groups did not change the specific growth rate in wet weight ( SGR w ), but the feed conversion efficiency ( FCE ) and protein efficiency ratio ( PER ) were significantly increased ( P  < 0.05) in comparison with control. The N and P consumed per unit wet weight gain of shrimp in S1, S2, S3 groups were significantly lower ( P  < 0.05) than control group by 15.39%, 15.96%, 19.33% for N, and 15.16%, 15.98%, 19.26% for P respectively. The total discharge of N and P (including N and P discharged by faeces ( F N/P ), non‐faecal excretions ( U N/P ) and exuviations ( E N/P ); ∑ F N / P + U N / P + E N / P) was significantly lower ( P  < 0.05) in the experiment groups by 19.91–22.07% for N and 18.68–26.37% for P respectively. Overall, the results suggest that the L . vannamei can reach completely compensatory growth, and the total discharge of N and P per unit wet weight gain of L . vannamei significantly decreased by cyclical feeding, which could have a positive effect on the reduced of environmental N and P loading due to the cultured of L . vannamei .