Comparative Growth Performance of Albino and Normal Pigmented Rainbow Trout (Oncorhynchus mykiss)

SUMMARY In this study, the growth performance, daily feed consumption, feed conversion ratio and condition factor of albino and normally pigmented rainbow trout {Oncorhynchus mykiss) under separate and mixed culture conditions have been compared. In addition the biochemical composition of meat and consumer acceptance of both variety have been evaluated. 150 albinos and 150 normally pigmented 0+ year class fish with a mean initial weight of 75 g rainbow trout were used. Experimental design was, pure normal (50), mixed (normal 25 + albino 25) and pure albino (50). Experiment was conducted as a three group with two replica for each group. At the end of the 120 days study period mean fish weights were 317.5±66.03 g (pure normal), 366.4±74.27 g (mixed normal), 3 15.3±44.63 g (mixed albino) and 3 19.9±50.26 g (pure albino). According to final mean weights it might be concluded that, mixed normal group has shown significantly better growth performance than the others (P <0,05)Mean daily feed consumption, feed conversion ratios and condition factors were not statistically significant among the groups. But feed conversion ratio in mixed group was found slightly lower than others. The biochemical analyses showed that, dry matter, ash, protein and fat ratios were not different between albino and normal rainbow trout. According to marketing trial results normal pigmented rainbow trout were preferred to albinos because of the color well known. As a result, there was no difference on growth performance of separately stocked albino and normal pigmented rainbow trout. But when the varieties have been stocked mixed, normal pigmented ones grows better than the albinos due to the variety's dominance. Key Words: Rainbow Trout, Oncorhynchus mykiss, Normal and Albino Pigmentation, Pure and Mixed Stock, Growth Performance, Feed Consumption, Feed Conversion Ratio, Biochemical Composition, Consumer Acceptance. VI