Effect of Replacing Fishmeal with Water Spinach (Ipomoea aquatica) on Growth, Feed Conversion and Carcass Composition for Nile Tilapia Fry (Oreochromis niloticus)

The use of alternative feeds aims to maintain productivity and reduce animal production costs. The objective of this study was to determine the nutritional value of Water Spinach (WS) (Ipomoea aquatica), as well as replacement of fishmeal (FM) by water spinach in diets for Nile tilapia fry, Oreochromis niloticus. To determine the growth performance of Nile tilapia fed different levels of water spinach, 150 fish (3.25±0.44g; 3.6±0.2cm) were randomly distributed in flow through system of 15 plastic aquariums each containing about 20 liters, and fed during 7 weeks with isoprotein (30% digestible protein) and isoenergetic (14.35 kJ g-1 digestible energy) diets containing replacement levels of 0, 25, 50, 75 and 100% of FM digestible protein by WS digestible protein. The experimental design was completely randomized with five treatments and three replicates. The protein efficiency ratio, absolute body weight, live weight gain and feed conversion ratio content significantly decreased in fish fed diets containing WS levels above 25%. Therefore, WS can replace up to 25% of FM without impairing juvenile Nile tilapia growth performance, feed efficiency, and body composition.

Keywords: Growth performance, Replacement, Water Spinach, Orechromis niloticus.