Effect of natural (carrot and beetroot) and artificial pigments (astaxanthin) on growth, blood indices, and colour changes in skin, tissue and blood in the diet of rainbow trout (Oncorhynchus mykiss)

Adhami, Batoul; Jafari, Sara; Janikhalili, Khosro

Effect of natural (carrot and beetroot) and artificial pigments (astaxanthin) on growth, blood indices, and colour changes in skin, tissue and blood in the diet of rainbow trout (Oncorhynchus mykiss)

Authors

batoul adhami ¹

sara jafari ¹

khosro janikhalili ²

¹ Master of sci. in Animal Sciences and Fisheries, Department of Fisheries, Sari Agricultural Sciences and natural Resources University

² Department of Fisheries, P.H.D student, Faculty of Animal Sciences and Fisheries, Sari Agricultural Sciences and natural Resources University

Abstract

A 30-day experiment was carried out to comparison the effect of carrot and beetroot as natural pigments and synthetic astaxanthin on growth performance, hematological parameters, and tissue color in rainbow trout fingerlings. 150 juvenile rainbow trout with initial mean weight of 21.44 ± 1.25g fed diets containing 50 and 100 mg/kg carrot; 100 mg/kg beetroot; 100 mg/kg synthetic astaxanthin and a control diet. Body weight increasing and specific growth rate were higher in fish fed the diet containing 100 mg beetroot than those of the control diet. Hematological study including red blood cell, white blood cell, hematocrit and hemoglobin showed significant differences between treatments (p<0.05). Carrot and beetroot had higher values of red blood cell, white blood cell, hematocrit and hemoglobin than those of the synthetic astaxanthin and control diet. Triglyceride and cholesterol value were significantly higher in diet containing 100 mg beet (p<0.05). Carotenoid content analysis from skin, tissue and blood revealed that inclusion of plant source of carotenoid including carrot and beetroot resulted in a significant increase in carotenoid concentration (p<0.05). The study concluded that plant source of carotenoid such as carrot and beetroot could improve immune systems in rainbow trout by increasing white and red blood cells and also, fish fed diet supplemented with natural carotenoid (carrot and beet) showed better coloration.

Keywords

Rainbow trout

Pigments

Blood and growth indices

Carotenoid