Influence of partial replacement of fish meal with shrimp head meal or cassava leaf meal, without or with lysine supplementation on growth performance of hybrid catfish (Clarias macrocephalus x C. gariepinus)

Fish meal (FM) were partly replaced by cassava leaf meal (CLM) or shrimp head meal (SHM) without or with lysine supplementation in practical diet for fingerling of hybrid catfish (Clarias gariepinusxC.macrocephalus) (3.8±0.5g). The control diet was based on FM (Ctr l), while the four experimental diets were: replacing 50% of FM by CLM without or with lysine supplementation (CLM, CLM-Lys); and similarly, FM was also replaced by SHM without or with lysine supplementation (SHM, SHM-Lys). Five diets were formulated to obtain isoenergetic (gross energy, 19 MJ kg^-1) and isonitrogenous diets (crude protein content, 300 g kg^-1). Each diet was test in three replicate groups of 30 fish during 60-day feeding trial. Results show that survival rates ranged from 93.3 to 96.7%. A highly significant difference in final weight (FW) and specific growth rate (SGR) between diets (p<0.001) were observed. FW and SGR were significantly higher for fish fed the SHM-Lys diet than the others. In contrary to SHM, replacing 50% FM results in low FW and SGR (p<0.001). Significant higher growth performance and SGR were observed in fish either fed CLM or SHM with lysine supplementation than that of fish fed diet without lysine supplementation. Feed efficiency ratio and protein efficiency ratio were not significantly affected across treatments (p>0.05). Concerning carcass composition, there was no significant differences in moisture, crude protein, ether extract and ash content.