growth of Nile tilapia (Oreochromis niloticus) fingerlings raised on commercial and farm-made fish feeds

Abstract

The study was conducted for 2 months (20th Feb to 6th April 2023) at Aquaculture Research and Development Center (ARDC)-Kajjansi which aimed on comparing the effects of feeding floating commercial and sinking farm-made fish feeds on the growth of Nile tilapia (Oreochromis niloticus) fingerlings reared in a fertilized pond system. A total of 600 fingerlings were randomly distributed and 100 fingerlings (mean mass of 5.48g) were stocked in each of the six hapas (measuring 2 × 2 × 1.5 m3) with mesh size 13 mm suspended in an earthen pond (2040 cm3) and each treatment was replicated in 3 happas. The fingerlings were fed a commercial floating and farm-made sinking fish feeds containing 42% and 41.7% crude protein respectively and the feeding rates of 8% of their fresh biomass in each hapa for the first 3 weeks and 7% until the end of the experiment. The results showed that, feeding O. niloticus fingerlings using either floating or sinking diets did not significantly affect growth and survival rate (p > 0.05) but there was significant increase in the final mass of the fingerlings from the stocking mass; that is from 5.48 ± 0.2g (mean ± S.E) to 36.9 ± 0.64 and 34.3 ± 0.66 for commercial floating and farm-made sinking fish feeds respectively. Equally, O. niloticus fed on sinking and floating diets had similar feed conversion ratio (p = 0.426). The fish in both treatments had similar condition factors and were growing isometrically (p > 0.05). However, O. niloticus fed on floating diet had significantly higher incidence cost by 39.8% more than feeding them on sinking diet (p = 0.001). Water quality parameters obtained were below the toxic levels which was favorable for the growth of the fingerlings like water temperature ranging from 23.0-26.8oC. The final fish mass (FW), daily growth coefficient (DCG), condition factor (CF), feed conversion ratio (FCR) and % fish survival (% survival) were calculated. The results in the experiment indicated that fingerlings fed with commercial feeding had slightly higher somatic growth than those fed using farm-made feed. The DCG, CF, FCR and % survival were similar among the treatments. It was cost-effective to grow Nile tilapia (O. niloticus) fingerlings using farm-made feeding during the experimental period under semi-intensive pond production at water temperature ranging from 20.8-26.2oC.