Phytase enzyme suplementation on performance and mineral retention in bones of silver catfish juveniles (Rhamdia quelen)

Abstract

Phosphorus (P) is one of the most expensive minerals in fish diets. Most of the P content in cereal grains and oil seed meals is bound to phytic acid as phytate. This study was conducted to evaluate the effects of adding increasing levels of dietary phytase on performance and bone mineral retention in juveniles of catfish. One hundred and twelve juveniles were used in a completely randomized design, with 4 treatments (0; 500; 1,000 and 1,500 FTU/kg diet) and 4 replications. Fish were fed at 10% of total body weight during a 45-day period. The following variables were evaluated: weight gain, standard length, survival, specific growth, body condition ratio, ash percentage, and P and Ca concentration in the bones. No significant effect was found for the increasing levels of phytase on these variables. It was concluded that dietary phytase (0 to 1,500 FTU/kg) do not affect the productive performance and minerals retention in the bones of the catfish juvenile.