Effect of dietary supplementation of astaxanthin on growth performance, survival and several of innate immunity parameters of rainbow trout (Oncorhynchus mykiss) larvae

High-density aquaculture has led to congestion and excessive stress and contributed to bacterial infection outbreaks that have caused high mortality. This experiment was conducted to evaluate the effect of dietary supplementation of astaxanthin on the growth performances, survival and several of innate immunity parameters of rainbow trout (Oncorhynchus mykiss) larvae for 60 days. In this experiment, 360 of larvae (with average weight of 0.13±0.01) in 4 treatments and 3 replicates (n=30 in each replicate) in a completely randomized design was divided and fed with diets containing 0, 50, 100 and 150 g astaxanthin /kg food respectively. The present results showed that diets containing astaxanthin showed a significant difference in growth, survival and innate immunity compared with control treatment (P<0.05). The highest FW, SGR, WG, PER, survival, total protein and globulin were observed in the diet containing 100 mg/kg astaxanthin which had a significant difference compared with other treatments (P<0.05). The highest lysozyme activity and albumin were observed in treatments containing 150 mg/kg astaxanthin which showed a significant difference compared with other treatments (P<0.05). Finally, the present results suggest that diets containing 100 and 150 g/kg dietary astaxanthin could improve growth, survival and innate immunity responses of rainbow trout.