Effect of Oregano and Cinnamon Essential Oils in Salmon Trout Fish Diets on Growth Performance and Meat Traits 1

Abstract This study was conducted to determine the effects of oregano and cinnamon essential oil supplementation in the trout diet (Oncorhynchus mykiss) on growth performance and meat quality. The experiment placed 96 trout fry fish in 12 controlled laboratory ponds. The water temperature was adjusted to 14 to 15°C, oxygen was 12.2 mg/liter, and water circulated continuously with the circulation system for 24 hours/day. Each aquarium included eight fish, which were fed twice daily. The experimental groups are as follows: 1: Control diet (basal diet, no supplementation), 2: addition of 100 mg/kg oregano essential oil (OEO), and 3: addition of 100 mg/kg cinnamon essential oil (CEO) in feeds. Performance traits, survival, activity in tanks, meat quality, blood components, meat fatty acid composition, and antioxidant activity were determined. The result of cinnamon and oregano essential oils did not have a significant effect on body weight, weight gain, and feed intake. The feed conversion ratio had a significant dissimilarity between the groups. There was no statistically significant effect among the groups regarding fish activity in the tank or interest in feeding. The best survival rate was in the CEO-supplemented group. The addition of OEO and CEO did not affect the carcass characteristics and fish meat's chemical composition (dry matter, crude protein, fat, ash, and fatty acid composition). No significant difference was observed in fish meat colors (L*: lightness, a*: redness, b*: yellowness), pH, cooking, and thawing losses. No significant effect was recorded in the blood lipid profile, glucose, AST, and ALT. Still, in the EO-supplemented groups, the serum lipid total protein ratio was lower than that of the control group. In conclusion, essential oils from oregano and cinnamon can be used without negatively affecting performance and carcass quality traits. However, they can increase the livability of fry trout fish.