Effect of dietary carob (Ceratonia siliqua) syrup on blood parameters, gene expression responses and ammonia resistance in tilapia (Oreochromis niloticus)

Abstract

In this study, carob (Ceratonia siliqua) syrup was supplemented in the diet of tilapia (Oreochromis niloticus), and its effects on growth performance, immunological and serum biochemical parameters, gene expression responses and ammonia resistance of the fish were investigated. Carob syrup was added to the fish diet in ratios of 0%, 5%, 2.5%, 1.25% and 0.625%, such that five different diets were prepared: control, Cerat5000, Cerat2500, Cerat1250 and Cerat625 respectively. The fish were fed with experimental diets for 60 days. The survival rate of fish fed with 5% carob syrup decreased compared with all other experimental groups. Thus, this study found that feeding tilapia fish with 1.25% carob syrup for 60 days increased gene expression responses, some innate immune parameters and ammonia resistance of the fish without negative effects on growth performance or serum biochemical variables.