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 (earthwormbased), (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