Influence of pond fertilization and feeding rate on growth performance, economic returns and water quality in a small-scale cage-cum-pond integrated system for production of Nile tilapia ( Oreochromis niloticus L.)

Abstract

The effects of pond fertilization and feeding rate on growth,economic returns and water quality were investigated to develop alow-costcage-cum-pond integrated system for production of Oreochromis niloticus (L.).Hand-sexed male fingerling save raging 19 0.39 and 32 0.69g were stocked in cages and open pond sat 150 fish cage 1and2 fish m 2 respectively. Fish were cultured for 114 day sin five triplicate treatments. Cages were in stalled into pond sand caged fish were fed a 24% protein diet at 3% (T1) and 6% (T2) body weight day 1 (BWD) without pond fertilization, and 6% BWD with pond fertilization (T3). The open water in the fourth treatment (T4) was not stocked but contained caged fish, which were fed 6% BWD for the first 57 days followed by3%BWD for the remaining period. Ponds in the control (T5) had no cages and were neither fertilized nor open-pond fish fed. Feeding rate and pond fertilization significantly (Po0.05) affected fish growth,profitability and water quality among treatments. Fish growth, feed utilization, fish yield, water quality and profits were significantly (Po0.05) better in T3 than the other treatments. It was concluded that fish production and economic returns were optimized at 6% BWD in fertilized ponds