Effects of different cinnamon powders levels in low and high carbohydrate diets on growth performance and the liver enzymes activity in rainbow trout (Oncorhynchus mykiss) juveniles

This study was carried out to evaluate the effect of different cinnamon powder levels in low and high carbohydrate diets on growth performance, liver histological changes, and the liver enzyme activity of rainbow trout (Oncorhynchus mykiss) juveniles. For this purpose, 360 rainbow trout with an average initial weight 16.12±1.33 (means±SD) were fed six diets supplemented with Diet1 (200 g/kg carbohydrate), Diet2 (200 g/kg carbohydrate, 30 g/kg cinnamon), Diet3 (200 g/kg carbohydrate, 50 g/kg cinnamon), Diet4 (300 g/kg carbohydrate), Diet5 (300 g/kg carbohydrate, 30 g/kg cinnamon), and Diet6 (300 g/kg carbohydrate, 50 g/kg cinnamon) for 8 weeks The results showed that fish fed Diet2 (62.64) and Diet3 (63.17) had higher weight gain as compared with treatments without cinnamon (p<0.05). Alanine aminotransferase and alkaline phosphatase were influenced by the experimental diet and the highest values were observed in Diet3 and Diet6 treatments (p<0.05), but the lowest content of aspartate aminotransferase was observed in Diet3 and Diet6 treatments (p<0.05). It is concluded that dietary cinnamon can improve growth performance and liver enzyme activity in fish fed a low-carbohydrate diet rather than a high one.