The effect of Levabon®diet supplement on growth efficiency and growth, immune and antioxidant related genes expression in common carp (Cyprinus carpio)

The aim of this study was to investigate the effect of Levabon® (autolyzed yeast, Saccharomyces cerevisiae) on growth efficiency, the expression of growth (IGF-I), immune (TNF-1α, LYZ) and antioxidant (CAT, SOD) related genes in the intestinal and liver tissue of common carp (Cyprinus carpio). The fish (n=240; 14.53 ± 0.67 g) were fed with 0.0, 0.3, 0.6, and 0.9% of Levabon® in 12 tanks (250 L) with three replicates (each with 20 fish) for 8 weeks. At end of experiment, fish were weighted and liver and intestinal tissue were collected. RNA was extracted from tissue samples and cDNA was synthesized and the expression of related genes was measured by real time PCR with specific primers. The results of measured experimental indices revealed that there is no significant difference in the growth performance and intestinal lysozyme (LYZ) gene expression among experimental treatments. The expression of TNF-1α, IGF-I, SOD and CAT genes in the intestinal and liver tissues showed a significant difference between the experimental treatments and the control, and the highest gene expression was observed in the 0.6% experimental treatment (P<0.05). Overall, these results suggested that inclusion of Levabon in common carp diet had no significant effect on growth performance but can beneficially effect on immune and antioxidant system.