Proximate composition of freshwater rainbow trout (Oncorhynchus mykiss) in relation to body size and condition factor from Pakistan

Eighty four farmed rainbow trout,oncorhynchus mykiss ranging from 4.8-38.5cm total length and 1.11-725.00g body weight were collected for analyses of its body composition from trout hatchery,masote near kali matti,murree and madian,swat. the condition factor value of o. mykiss ranged from 0.831 to 1.607. the mean percentage of water was found 77.82%,for ash 12.77%,for fat 22.79% and for protein content 64.42% in whole dry body weight of o. mykiss. results showed that there was a strong correlation (p<0.001) in each of these body constituents (water,fat,protein and ash) with body size,weight and condition factor of the fish. thus,with increasing body size,fat and protein contents increased in greater proportion,while ash and water percentage decreased. an inverse correlation was found in water and ash percentages,whereas percentage fat and protein showed positive correlation with condition factor. © 2016,university of agriculture. all rights reserved.