Effect of different sex, length and weight on carcass quality in Onchorhynchus mykiss

The amount of chemical composition in the body of aquatic animal depends on the type of nutrition,,environment, age and sex of the living organism. The aim of this study was to investigate the carcass composition (protein, fat, moisture and ash) in rainbow trout with weight, length (50 ± 10 g, 250 ± 10 g and 600 ± 10 g weight groups and 12 ± 5 cm, 22 ± 5 and 38 ± 5 cm) and different genders were performed. The results of comparing the weight and length groups showed that the amounts of protein, fat, moisture and ash of fish carcasses were significantly different between different groups (P <0.05), the fish that had the highest length and weight, the amount of protein and fat was in the highest amount (P <0.05) and the inverse relationship between ash and moisture was observed and no significant difference was observed between the 50 and 250 g groups (P> 0.05). The results of different gender showed that the amounts of protein, fat, ash and carcass moisture of fish were significantly different between different groups (P <0.05) so that in males it was significantly higher than females. The results of the present study showed that in rainbow trout, the effect of length, weight and gender on carcass composition was significant and fish with 600 g and an average length of 38 cm had better quality. Also, the amount of protein, fat, ash and moisture in males is significantly higher than females of rainbow trout.