标题：Differential Effects of Dietary Lipids on Growth Performance, Digestibility, Fatty Acid Composition and Histology of African Catfish (Heterobranchus longifilis) Fingerlings
摘要：The present study was performed to investigate the influence of fish oil (FO), two terrestrial animal fats (lard (PL) and poultry oil (CF)) and three vegetable oils (palm kernel (PKO), sheabutter (SBO) and sunflower (SFO)) as the dietary lipid sources on the growth performance, nutrient digestibility, fatty acid (FA) composition and histology of Hetero-branchus longifilis. Six isonitrogenous and isoenergetic diets containing 6% of added fat from the lipid sources were formulated and used. Each diet was fed to triplicate groups of 20 fish. The lipid source influenced (P < 0.05) weight gain, specific growth rate, feed conversion ratio, hepatosomatic index and nutrient digestibility. Liver morphology of H. longifilis fed CF showed intense steatosis with hepatocytes containing numerous lipid vacuoles. However, fish fed PKO and SFO showed regular-shaped hepatocytes with few lipid vacuoles in the cytoplasm. Fillet FA profile of fish fed PKO, SBO, PL and CF diets had significantly higher (P < 0.05) concentrations of SFA and MUFA, but lower PUFA com-pared to fish fed FO and SFO diets. Fillet of fish fed the FO diet had higher (P < 0.05) concentrations of EPA and DHA compared with fish fed the other diets. The results of this study shows that alternative lipids sources could be used in H. longifilis diets however, inclusion of PKO or SBO in the diet of H. longifilis produced fillets with low concentrations of long chain n-3 PUFA.
