Growth performance and feed utilization of Nile Tilapia (Oreochromis niloticus L.) fed on commercial and farm-made feeds in ponds

Abstract

The growth performance of Nile tilapia (Oreochromis niloticus) fingerlings were compared between fish fed with commercial feed and formulated farm-made feeds in ponds. The experiment was conducted in duplicate ponds, each measuring 50 m2 at a stocking density of 2 fish/m² based on a completely randomized design (CRD). Before the commencement of the actual experiment stocked fish were left to acclimatize in ponds for about two weeks. All fish were fed 3% of their body weight per day, and the ration was given twice a day in the morning (10:00 am) and afternoon (4:00 pm) for all treatment groups. The initial size of the fish was made uniform (mean size of 10.35–11.43 cm TL and mean TW of 24.7–31.9 g) at the beginning of the experiment and samples of 50% of stocked fish were measured monthly to follow the growth rate and adjust the daily ration accordingly. Total length (TL) and total weight (TW) of sampled fish were taken to the nearest 0.1 cm and 0.1 gm, respectively on monthly basis from September 2019 to March 2020 for a period of six months. Fish fed with commercial feed (27% CP) showed the highest daily growth rate (0.40 g/fish/day) followed by fish fed with either feed II (SYB, 0.28 g/fish/day) or feed III (EWB, 0.28 g/fish/day). The results of the experiment showed significant variations on the growth of fish between the commercial feed and the two farm-made feeds, feed II (soya bean-based) and feed III (earthworm-based), (p<0.01) but no significant growth variation was observed between the two farm made feeds (p=0.147). The feed conversion ratio (FCR) values computed for both commercial and farm-made feeds were high ranging from 2.84–4.85 indicating the poor utilization of the feeds by the fish. Thus, the low growth rate of O. niloticus fingerlings recorded in this study might be attributed to the combined effects of low quality feed ingredients used and unfavourable physico-chemical environment of the pond. The overall survival rate was high and varied from 80.2% to 92% per treatment. Some physico-chemical parameters such as low water temperature, and alkaline pH might have contributed for the poor growth of the fish. Therefore, future studies should focus on formulating complete quality feeds and management of pond environment which promote better growth and production of O. niloticus.