Digestible protein requirements for maintenance, growth, and efficiency of protein utilization in pacu (Piaractus mesopotamicus) juveniles: an exponential nitrogen utilization model

The present study aimed to estimate digestible protein (DP) requirements for maintenance and growth assess the efficiency of utilization in pacu (Piaractus mesopotamicus) juveniles. A complete randomized design consisted seven treatments, five replicates (tanks) per treatment was used. After a one-week acclimation period, 350 juveniles 27.48 ± 1.8 g (initial average body weight - BW) were equally distributed among 35 tanks (10 fish tank) 450 L. Fish fed with graded levels (64.5, 111.8, 164.6, 217.1, 264.4, 316.2 369.5 kg-1) three times day until apparent satiation 120 days. monomolecular model parameters including nitrogen requirement (NMR) (37.76 mg BW0.67 kg-1 d-1), daily deposition (ND) (194.8 intakes (based on metabolic 1638, 1902, 2241 kg-1BW0.67 d-1 75, 80 85% maximum theoretical retention (NRmaxT), respectively (529×10-6) estimated through relationship between intake (NI) ND. 80, NRmaxT as 187, 217, 256 by based feed 2% live BW