Nutritive value of diet containing dried lactic acid fermented fish silage and soybean meal for juvenile Oreochromis niloticus and Clarias gariepinus

Abstract

Dry diets containing varying levels of dried fermented fish silage and soybean meal blend (FS: SBM) as replacement for 25,50 or 75% of fish meal protein were fed to juvenile Oreochromis niloticus (8.2 ± 0.1 g) and Clarias gariepinus (10.8 ± 0.3 g) at 5% body weight per day for 70 days. Diets containing co-dried FS: SBM supported weight gains and growth rates similar to those in the control treatment without significant differences (p > 0.05). Feed conversion, protein efficiency ratio and protein productive values followed a similar trend with growth performance values. Apparent protein digestibility decreased in both fish species with increasing dietary level of co-dried FS: SBM Carcass composition of experimental fish were not affected by the diets and morphological defects were not observed. Results indicate that co-dried FS: SBM can partially replace fish meal protein as well as establish the potential of utilizing waste/undersized tilapias as a protein feedstuff in dry aquaculture diets.