Evaluation of oregano (Origanum vulgare L.) essential oil effect on growth indices and fillet quality of rainbow trout (Oncorhynchus mykiss) during refrigerated storage (4±1 °C)

This study evaluated the effects of diets including different levels of oregano (Origanum vulgare L.( essential oil on growth indices and fillet quality of rainbow trout (Oncorhynchus mykiss) during refrigerated storage (4±1°C). For this purpose, rainbow trout with an average weight of 69.38±0.44 g were fed with diets containing 0, 250, 500 and 750 mg kg-1 oregano essential oil for 48 days. After the end of 48 days, growth parameters were measured and also some fishes of experimental groups were filleted and stored at refrigerator (4±1˚C) for 21 days due to quality investigation. Total psychrophilic counts, TBA and TVB-N analyses were done every 7 days (day 0, 7, 14 and 21). The results showed significant differences in some growth parameters including final weight, weight gain, weight gain percent and feed conversion ratio among experimental groups (P