Small crumbled diet versus powdered diet in restricted feeding management of juvenile Nile tilapia

José Nacélio   Oliveira-Segundo; Francisco Roberto dos Santos   Lima; Michael Masaki Freitas   Akao; Marcelo Vinícius  do Carmo e Sá

Small crumbled diet versus powdered diet in restricted feeding management of juvenile Nile tilapia

Autores

José Nacélio Oliveira-Segundo

Francisco Roberto dos Santos Lima

Michael Masaki Freitas Akao

Marcelo Vinícius do Carmo e Sá

Editor

Universidade Estadual de Maringá

Descripción

The pellet size of the diet can affect both fishgrowth performance and the water quality of therearing units. The present work assessed the effects of feeding juvenile Nile tilapia,Oreochromis niloticus(L.) asmall crumbled diet (SCD; 0.8 mm) on water quality and growth performance. Fish werereared for six weeks intwenty 250-L polyethylene outdoor tanks at a density of 10 juveniles tank-1(40 fish m-3).There were two feedingrates (standard and restricted) and two types of artificial fish diet (powdered and SCD). The standard feedingrates were reduced by 30% for restricted feeding. The concentrations of free CO2,reactive phosphorus, totalammonia nitrogen (TAN) and nitrite were higher in the full-fed tanks relative to the restricted-fed tanks. In thestandard feeding rate groups, those tanks fed SCD hadlower TAN and nitrite concentrations than tanks fed apowdered diet. The final body weight and specific growth rate of fish fed a restricted SCD were higher than thefull-fed tanks. The higher levels of food waste in the powdered-diet tanks lead to impairment of fish growthperformance.