PARTIAL REPLACEMENT OF FISHMEAL WITH TUNA LIVER MEAL IN DIETS FOR COMMON CARP FRY, CYPRINUS CARPIO L. 1758

Tuna liver meal (TLM) was tested to replace fish meal (FM) in diets for carp fry, Cyprinus carpio Linneus, 1758. Triplicate groups of fish with average weight of 0.32 ± 0.65g were fed each of six isonitogenous (42%), isolipidic (16%) and isoenergetic (18 KJ DE g-1) diets prepared to include 0, 10, 20, 30, 40 and 50% (diets 1- 6, respectively) of FM protein being substituted by TLM. The control diet contained fish meal (17.14%) and soybean meal (46.9%) as the main sources of dietary protein. After 13 weeks of feeding, fish fed diet 2 and diet 3 exhibited the highest (P<0.05) values for live weight gain, specific growth rate, condition factor, better feed conversion ratio and protein efficiency ratio compared to the others. Survival range was from 70 to 87.5%. However, fish fed diet 6 exhibited lower growth and survival than those fed other diets. Apparent protein and lipid digestibility values for fish fed diet 2 or diet 3 were higher than the others. There were no significant (P>0.05) differences in the crude protein and ash content in the whole-body. However, moisture and lipid contents were significantly (P<0.05) affected by dietary treatments. These results indicate that up to 20% of FM protein in fish diet can be replaced by TLM without adverse effects on fish growth, feed utilization and body composition