The effects of different feeding rates on growth and feed conversion of rainbow trout (Oncorhynchus mykiss) reared in sea cages in Black Sea (sinop), Turkey

Abstract

In the research, rainbow trout with a mean weight of 123 g were fed 1.5-1.8% (1. group) and 2.25-2.7% (11. group) of the body weight and adlibitum (III. group), respectively to investigate the effects of different feeding rates on growth and feed conversion. At the end of the experiment, final average weights of 411.3+/-10.08 g, 484.2+/-14.23 g and 513.5+/-14.93 g, have been obtained, respectively. The difference between the I. group and II. group, and also the I. group and III. group was found significant (p<0.05) while the difference between the II. group and III. group insignificant (p>0.05) according to the results of variance analysis and Duncan tests. Daily growth rates in the groups were obtained as 3.12%, 3.86% and 4.18%. Feed conversion rates of 1.10, 1.54 and 1.92 were obtained in the experimental groups, respectively. It has been concluded that feed conversion in the I. group fed on 1.5-1.8% body weight, was best. That was followed by the II. and Ill. group. At the end of the experiment, condition factors of 1.29-0.03, 1.333+/-0.03 and 1.38+/-0.04 were determined while mortality rates of 4.17%, 13.75% and 17.92% were recorded, respetively.