Substitution effect of fish meal with various sources of animal by‐product meals in feed on growth, feed utilization, body composition, haematology and non‐specific immune response of olive flounder ( Paralichthys olivaceus , Temminck & Schlegel, 1846)

Abstract

Suitability of various animal by-product meals was evaluated as an alternative source for fish meal (FM) in olive flounder feed when 30% FM was substituted. Juvenile fish (n = 480) was distributed into 24 flow-through tanks. Seven experimental diets were prepared. 65% FM and 12% soybean meal were included as the protein source in the control (Con) diet. Thirty per cent of FM was substituted with tuna by-product, chicken by-product, hydrolysed chicken offal, meat, meat and bone, and blood meals, referred to as the TBM, CBM, HCOM, MM, MBM and BM diets respectively. Each diet was hand-fed to satiation for 8 weeks. Weight gain, specific growth rate (SGR) and feed efficiency ratio (FER) of fish fed the TBM diet were greater than those of fish fed all other diets. Weight gain, SGR and FER of fish fed the Con diet was also greater than those of fish fed the MM and BM diets. The proximate composition of the whole body fish was unaffected by the experimental diets. Lysozyme activity of fish fed the Con, TBM and CBM diets was higher than that of fish fed the MM and BM diets. Amino acid profiles of fish were not affected by the experimental diets except for tryptophan. All fatty acid profiles of fish except for eicosadienoic acid were affected by the experimental diets. In conclusion, tuna by-product and chicken by-product meals are the good substitutes for FM in olive flounder feed when 30% of FM at 65% in diet was replaced with animal by-product meals.