Influence of dietary palm oil on growth and carcass composition of Heterobranchus longifilis

Supplies of marine fish oil (FO) are limited and continued growth in aquaculture production dictates that substitutes must be found that do not compromise fish health and growth. This study investigated the suitability of palm oil (PO) as a replacement for FO (cod liver oil) in diets of H longifilis. Triplicate groups of H longifilis fingerlings were fed five practical-type diets in which the added lipid was either 100% FO and 0% PO; 75% FO and 25% PO; 50% FO and 50% PO; 25% FO and 75% PO; or 0% FO and 100% PO for 8 weeks. There were no significant effects of diet on growth rate or feed conversion ratio. Lipid deposition was highest in the liver of fish fed 100% PO. No significant differences were observed between dietary treatments for moisture, protein and ash content in H. longifilis fingerlings. This study suggests that PO can be used successfully as a substitute for cod liver oil in diets for H. longifilis