Addition of Phytase Artificial Feed to Increase Digesting, Specific Growth and Survival Rate of Nile Tilapia fingerlings (Oreochromis niloticus)

Abstract

The aims of this study were to examine the effects of phytase enzym and to determine the optimum dose of phytase enzym in artificial feed on digesting, specific growth rate and survival rate of Nile Tilapia fingerlings (Oreochromis niloticus). Nile Tilapia fingerlings (O. niloticus) used in this study were 120 animals with the weight of 3±0.02 g/animal. The fingerlings were raised in 6 weeks with the density of 1 animal/liter. Methodology used in this study was laboratory treatments with complete random design. The study consisted of four treatments and three repetitions. The treatments were addition of phytase enzym in artificial feed with the different level of doses; those were A (0 mg/(kg of feed)), B (500 mg/(kg of feed)), C (1.000 mg/(kg of feed)), and D (1.500 mg/(kg of feed)). The artificial feed with 30% protein content was in the dried and crumb pellet form which was added phytase enzym in every treatment. Data collected were specific growth rate, feed conversion ratio, protein efficiency ratio, raw protein digesting rate, total protein digesting rate, survival rate and water quality. Varian annalysis was used in this study. If the results were significant (p<0.05) and highly significant (p<0.01), double Duncan area test was conducted to determine the mean of different treatments. In order to find the optimum effect polynomial orthogonal test was used. Descriptive analysis was used to explain raw and total protein digesting rate and water quality. The results show that the addition of phytase enzym in artificial feed significantly affected on the specific growth and feed utilization ( feed and protein efficiency ratios); however, it did not significantly affect on the survival rates. The optimum dose of phytase enzym in artificial feed on the specific growth and feed utilization was at the level of 1,000 mg/(kg of feed). This level resulted in the highest of raw and total protein digesting rates of Nile Tilapia fingerlings (O. niloticus), compared to B, D, and A treatments. The raw and total protein digesting rates were of 84.88% and 71.27%. The water quality during study was in viable range for the Nile Tilapia fingerlings (O. niloticus) cultivation. Keywords : Nile Tilapia (Oreochromis niloticus), Phytase Enzym, Digesting, Specific Growth, Survival Rate