<b>Liquid phytase in extruded diet for juvenile Nile tilapia (<em>Oreochromis niloticus</em>)</b> - DOI: 10.4025/actascianimsci.v29i4.1016

Abstract

This study was undertaken to evaluate the effects of liquid phytase on the performance of juvenile Nile tilapia. It was used 176 fish (45.84 ± 3.31 g). The fish were fed diets without phytase and with 250; 500 and 1,000 phytase units (PU) kg^-1 of diet, during 62 days. A control diet was used containing 3,012 kcal digestible energy kg^-1, 29% crude protein and 0.23% available phosphorus. The fish were assigned to a randomized block design, with four treatments and four replications. No effect was observed on the levels of dietary phytase on feed intake, hepatosomatic index, visceral fat, survival, as well as on the retention of bone calcium, carcass moisture, crude protein and ash. A linear increase was observed in phosphorus retention and on the apparent digestibility coefficients of dietary crude protein and phosphorus. A quadratic effect was observed for weight gain, feed conversion ratio, protein efficiency ratio, carcass yield and carcass fat, which increased up to 350; 500; 500; 516 and 647 PU kg^-1, respectively. It was concluded that the use of 500 PU kg^-1 is adequate in diets for juvenile Nile tilapia.