Research Article
Tewodros Abate Alemayehu an
Abstract
In this study, the growth performance and survival rate of Nile tilapia (Oreochromis niloticus) subjected to different feeding frequencies were evaluated in cage culture. Juveniles with mean initial weight of 35.99 ± 0.23g were stocked in 1 m3 net cages and assigned to a duplicate of 50 fish in a completely randomized design in six treatments. T1 were fed 3% of their body weight divided into four equal meals per day for the first three months and then allowed to feed two times a day for the next three months; T2 and T3 were fed 3% of their body weight divided equally at frequency of four and two feedings/day, respectively, throughout the experiment. Feed was given once a day (without dividing) for T4 and once every other day (without dividing) for T5 throughout the experiment. All treatments were fed pelleted diet except the control groups in which fish were provided with only the natural food. The mean specific growth rates (SGR), Feed conversion ratio (FCR) and Feed conversion efficiency (FCE) were statistically similar for T1 and T2, but they were higher than T3, T4 and T5. However, mean weight gain, mean daily gain and Condition Factor (CF) showed a significant difference (P<0.05) among experimental groups. In conclusion, growth performance and net yield were increased with increased feeding frequency, so frequent feeding was recommended for optimum result of O. niloticus in cage culture. It was also revealed that cage culture at experimental level has no effect on the water quality and plankton abundance.