Growth Performance Of Nile Tilapia (Oreochromis niloticus) Fed on Ipomoea Aquatica
Feed is one of the major costs of aquaculture operations, constituting between 30 – 70% of the total operating budget depending on the intensity of the operation. To this end, research into cheaper feed constituents (especially of the more expensive fishmeal) has been ongoing for decades. The potential of Ipomoea aquatica (water spinach) as an alternative to commercial feed (Raanan) in the intensive culture of Oreochromis niloticus was evaluated in a concrete tank system behind the Faculty of Science Complex of the University of Cape Coast from 4th April to 1 st October, 2016. Raanan Commercial Feed (Raanan), Dry Whole Ipomoea (Dry) and Fresh Leaf Ipomoea (Fresh) were the diet types used whereas the Control was not fed. Growth data were taken on a bi-weekly basis and used to determine the growth performance and survival of the studied Oreochromis niloticus. Raanan fed fish had significantly higher protein (28.801 ± 0.292) and lipid content (3.437 ± 0.183) than Dry (20.095 ± 0.07 & 0.832 ± 0.481, respectively). In terms of growth parameters, Ranaan again had significantly (p ˂ 0.05) higher values in every category: Specific Growth Rate (SGR) of 1.617 ± 0.035 followed by No Feed with 0.466 ± 0.076; Absolute Growth Rate (AGR) of 0.570 ± 0.002 with No Feed having 0.024 ± 0.011 and Percentage Weight Gain (PWG) of 2252% ± 164 while No Feed had the second highest weight gain of 150.6% ± 36.7. Terminal survival did not vary significantly across treatments with Dry having 88.89 ± 7.35%, Raanan and No Feed treatments recording 83.33 ± 4.81% and Fresh having the lowest of 69.44 ± 10% respectively. Raanan had a significantly higher Condition Factor (CF) 1.601 than any of the treatments as shown: Fresh (1.4977), Dry (1.4853) and No Feed 1.4645 which did vary significantly. The Length-Weight Relationship of all the treatments showed isometric growth. There were significant differences in the ANOVA results of the carcass proximate analysis of fingerlings and adults. In conclusion, the two forms of Ipomoea aquatica tested in this study did not result in good growth performance of O. niloticus while the Raanan commercial feed proved its efficacy as a commercial feed of choice. Some recommendations were then made.
