Growth Performance, Chemical Composition of Fillets, Liver and Intestinal Histology, and Expression of Lipid-Dependent Genes in Common Carp (Cyprinus carpio) Fed Artificial Diets

Abstract

The study is a preface to redesign farming of carp, and the aim was to determine the influence of three artificial feeds on carp growth performance, chemical composition, intestinal and liver histology, and the expression of two main genes of fatty acid catabolism: acyl-coenzyme A oxidase 1 (acox1) and peroxisome proliferator-activated receptor  (ppar). The 61-days trials were run in set of 9 floating cages in triplicate (n=3 per diet). The results showed that zootechnical parameters (i.e. feed conversion ratio, protein efficiency ratio) significantly improved with increased level of fat in diet, for instance, the lowest FCR was noted for fish fed diet A (9.900.23% of fat). Additionally, gene expression analysis revealed that activity of acox1 and ppar in the liver depend on the fat level in carp diet. The expression of ppar and its target gene acox1 in the intestine of fish showed a distinct pattern in relation to liver samples, since feeds with high and low levels of fat exerted a comparable effect on the mRNA level of the studied genes. In conclusion, this study showed that the level of fat in common carp diets correlated with the level of lipids in the meat.