Effects of date (<em>Phoenix dactylifera</em> L.) kernel essential oil on growth performance and innate immunoassay in rainbow trout (<em>Oncorhynchus mykiss</em>) juveniles

Abstract

This study aimed to investigate the effects of date (Phoenix dactylifera L.) kernel essential oil on growth and development performance parameters as well as phagocytic activity, respiratory burst activity, superoxide dismutase, lysozyme activity, and myeloperoxidase activity from immune parameters of rainbow trout (Oncorhynchus mykiss). The nutritional study was performed for 45 days to assess the effect of three concentrations (0.5, 1, and 2 mL kg-1) of date kernel essential oil in rainbow trout. β-citronellol, an important compound in many respects, was found 31.70% in date kernel oil. It has been determined that the addition of date kernel essential oil to rainbow trout feed decreases the feed conversion rate, increases the percent body weight gain, and the specific growth rate. It was observed that phagocytic activity, respiratory burst activity, and myeloperoxidase activity values improved in date kernel essential oil added groups, however, superoxide dismutase and lysozyme activity values were not affected. Consequently, date kernel essential oil can be act as a growth promoter, increase innate immunity, and cheap feed additive for the rainbow trout juveniles.