Evaluation of Dietary Fishmeal Analogue with Addition of Shrimp Soluble Extract on Growth and Nonspecific Immune Response of Rainbow Trout, <i>Oncorhynchus mykiss</i>

Abstract

Abstract A 12‐wk feeding trial was conducted to evaluate the effects of the dietary fishmeal analogue ( FMA ) adding 2% shrimp soluble extract ( SSE ) on growing rainbow trout, Oncorhynchus mykiss . Fish averaging 146 ± 3.8 g (mean ± SD ) were randomly distributed into 500‐L aquaria as groups of 20 fish per tank. Fish were fed the experimental diets in triplicate groups to apparent satiation twice a day on a dry matter basis. Each group was fed one of the four experimental diets: control (FM100% + FMA0%), FMA 0 (FM100% + FMA0% + SSE2%), FMA 12 (FM88% + FMA12% + SSE2%), and FMA 24 (FM76% + FMA24% + SSE2%). After the feeding trial, weight gain and specific growth rate of fish fed the FMA 0 and FMA 12 diets were significantly higher than those of fish fed the FMA 24 diet ( P &lt; 0.05). Feed efficiency and protein efficiency ratio values of fish fed the control, FMA 0 , and FMA 12 diets were significantly higher than those of fish fed the FMA 24 diet ( P &lt; 0.05). The values of superoxide dismutase activity showed significantly higher amounts for the FMA 0 , FMA 12 , and FMA 24 groups than the control group ( P &lt; 0.05). Lysozyme activity in the FMA 12 group was significantly higher than in the control group ( P &lt; 0.05). Therefore, according to our results, FMA with additive SSE can be used up to 12% as a substitute of fishmeal for growing rainbow trout.