Hepatic biochemical, morphological and molecular effects of feeding microalgae and poultry oils to gilthead sea bream (Sparus aurata)

The present work investigated how the combination of poultry oil with microalgae oils, rich in eicosapentaenoic acid and docosahexaenoic (ED diets) or n-6 docosapentaenoic n-3 (DD modulates hepatic lipid metabolism gilthead sea bream juveniles. Diets were tested using two different fishmeal contents (15% 7.5%) compared against a fish oil-based diet (CTRL) negative control diets based on as source (PO diets). After 74 days feeding, fed 15% FM ED DD showed similar daily growth index to those CTRL, while PO caused reduced growth. Fish livers reflected highest long-chain polyunsaturated fatty acids when diets, which down-regulated fas, scd-1a, fads2, lpl cpt1, reducing accumulation hepatocytes size. In contrast, lowest deposition oleic liver, leading hepatosomatic due increased liver lipids. Therefore, these revealed severe steatosis associated an expression lipogenesis-related genes, particularly sbrep1. Furthermore, seemed activate desaturation pathways livers, by that are products from desaturases fads2 scd-1a expressions. reduction dietary content 7.5% lowered growth, although be more affected FO replacement than replacement. Combining could alternative essential marine diets.