Effects of astaxantin on growth performance, survival rate, and lipid peroxidation in rainbow trout (Oncorhynchus mykiss)

This study aimed to investigate the effects of dietary astaxanthin supplement on survival rate, growth performance and lipid peroxidation of rainbow trout, Oncorhynchus mykiss during the first-feeding period. Fish fry with a mean initial weight of 198.50 mg were fed diets supplemented with 50 and 100 mg astaxanthin per kg feed for 120 days. Results showed that 100% survival rate was observed in all groups. Higher final weight and length compared to the control group were shown in both treatment groups. Significantly lower feed conversion ratio with lowest level in high dose group were noted in the treatment groups compared to the control group. Both specific growth rate and condition factor were significantly higher in both treatment groups in comparison with the control group. Carcass weight showed the same pattern as specific growth rate and condition factor with high levels in both treatment groups and highest level in high dose group compared to the control group. Remaining parameters, including hepatosomatic index, spleen somatic index and viscerosomatic index did not show significant changes in comparison with the control group. The total product of lipid peroxidation indicated as malondialdehyde (MDA), significantly decreased in both treatment groups. The results indicate that feeding astaxanthin at 50 and 100 mg per kg feed has a potential to enhance growth performance and decrease lipid peroxidation in rainbow trout during the first-feeding period.