The Impact of Dietary Phytase on the Protein Efficiency Ratio and Growth of Tilapia (Oreochromis niloticus)

The main challenge in tilapia rearing (Oreochromis niloticus) is the high cost of feed. To address this, using local raw materials in making feed is an attempt to reduce costs. However, the presence of phytic acid content can hinder fish growth, so the addition of phytase becomes necessary. The purpose of this study was to investigate the impact of dietary phytase on protein efficiency ratio and tilapia growth. This research was conducted in Loka Muntilan, Magelang, Central Java, Indonesia. A total of 240 tilapias with an average weight of 12.88±0.2 g/fish were used for this study. Four treatments, namely treatments A, B, C, and D, were implemented with phytase additions of 0; 0.25; 0.5; and 0.75 g/kg of feed, respectively. The results revealed that dietary phytase significantly influenced total feed consumption (TFC), feed conversion ratio (FCR), feed utilization efficiency (FUE), protein efficiency ratio (PER), and relative growth rate (RGR) values (P = .05), but not the fish survival rate (P = .05). The most favorable outcome was achieved with a phytase dose of 0.75 g/kg of feed (i.e., treatment D), with the following values: TFC 548.74±2.58 g, FCR 1.38±0.03, FUE 70.11±0.69%, PER 2.33±0.02%, and RGR 2.65±0.04% per day, respectively.