Effects of replacing fishmeal with soybean protein concentrate (SPC) on growth, blood biochemical indexes, non-specific immune enzyme activity, and nutrient apparent digestibility for juvenile Litopenaeus vannamei

An 8-week feeding trial was conducted to investigate the effects of dietary soy protein concentrate (SPC) levels on growth, blood biochemical indexes, non-specific immune enzyme activity, and nutrient apparent digestibility for juvenile Litopenaeus vannamei (initial weight 0.44 ± 0.002 g). They were formulated by replacing 0% (the control), 10%, 20%, 30%, 40%, 60%, and 80% of fish meal (FM) protein with SPC (designed FM, S11, S22, S33, S44, S55, and S66, respectively). With the replacement level of SPC in the diet was higher than 30%, weight gain (WG) and specific growth rate (SGR) for juvenile Litopenaeus vannamei significantly decreased ( P