Turkish Journal of Veterinary & Animal Sciences




The effects of diets including various natural carotenoid sources and synthetic astaxanthin on the pigmentation and growth of rainbow trout (Oncorhynchus mykiss) were investigated. Rainbow trout weighing about 111 g were fed diets containing 1.6%, 2.4% and 3.2% marigold flower; 4.4%, 6.6% and 8.8% red pepper; 100 mg kg^{-1} synthetic astaxanthin; and a control diet for 60 days. At the end of the experiment, synthetic astaxanthin provided the highest carotenoid accumulation in the fish flesh (6.42 mg kg^{-1}) in the groups. This was followed by red pepper (5.78 mg kg^{-1}) and marigold flower (5.59 mg kg^{-1}), each of which included equal levels (100 mg kg^{-1}) of carotenoids (P < 0.05). The fish fed marigold flower experienced yellow pigmentation, which was remarkably different from the other groups. An addition level of 2.4% or higher marigold flower and 6.6% or higher red pepper into the diet had negative effects on growth performance (P < 0.05). It can be concluded that the most appropriate dietary doses of marigold flower and red pepper for pigmentation of rainbow trout are 1.6% and 4.4%, respectively.


Pigmentation, Oncorhynchus mykiss, red pepper, marigold flower

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