Impact of a plant-based diet supplemented with phytase on growth, tissue energy and bone mineral status of juvenile pacú ( Piaractus mesopotamicus )

Abstract

The effects of fishmeal free plant-based diets and dietary phytase supplementation on growth, hematology, plasma, muscle, and liver composition, and bone mineral status of juvenile fish Piaractus mesopotamicus were studied. Two hundred and ten fish (13.70 ± 0.61 g) were maintained in a recirculating system (22 ± 1°C) and fed with two diets: plant-based experimental diet (ED) and plant-based experimental diet added with microbial phytase (EDP) for 120 days. Both treatments were replicated three times. Fish were fed twice a day at a readjusted-restricted rate (5% biomass weight per day). Growth performance measurements were carried out every 21 days. The activity of phytase after extrusion was 4001.1 ± 160.0 PU/kg diet. No significant differences in growth, morphometrical and hematological biomarkers, and tissue energy composition were detected. Lipid content of muscle decreased in EDP-fed fish. There was a higher content of zinc in EDP-fed fish, but there were no differences in bone weight, ash, calcium, and phosphorous content.