The effect of growth and antioxidant enzyme activities of garlic (Allium sativum), sage (Salvia officinalis) and oregano (Origanum vulgare) added to the feed in rainbow trout

In our country, three important species, sea bass, sea bream and trout, are produced in aquaculture production and the highest production amount among these species belongs to trout. Antibiotics used for treatment cause unwanted side effects. Few licensed products are allowed today due to the widespread use of antibiotics. In the European Union, after 2006, it has been prohibited to add antibiotics to feeds for prophylactic purposes. Therefore, it is reported that medicinal plant species can be used as natural antibacterial products against pathogenic bacteria as alternative products. It has been known for many years that medicinal plant extracts and essential oils have antimicrobial properties on some bacterial and fungal species. In this study, antioxidant enzyme activity and growth values were determined in rainbow trout fed with garlic, origanum and sage powder and oil supplemended diets. Essential oils and plant powders at dietary levels of 1% and 5% added to basal diet respectively. The results showed that fish fed garlic powder and oil had significantly higher final weight gain than control and other groups. Suplementation of Origanum powder and oil had a higher catalase activity when compared with the control group (P<0.05).