Work

Effects of replacing fish meal with a combination of corn protein concentrate and meat meal on growth performance, biochemical profile, digestive enzyme activity, antioxidant activity, immune response, and economical efficiency in juvenile black rockfish (Sebastes schlegelii)

Year: 2026

Type: article

Abstract: This study evaluated the effects of substituting fish meal (FM) with a 1:2 blend of corn protein concentrate and meat meal (CCM) on growth performance, digestive enzyme activity, biochemical composition, antioxidant and immune responses, and economic efficiency in juvenile black rockfish ( Sebastes schlegelii ). Seven experimental diets were prepared: a control diet containing 65 % FM and six test diets with 10 %, 20 %, 30 %, 40 %, 50 %, and 60 % of FM from the control diet progressively replaced with CCM. Juvenile rockfish (initial body weight: 3.6 ± 0.01 g) were randomly assigned to triplicate groups of 30 each and fed the experimental diet for 8 weeks. Growth parameters, including final body weight, weight gain, specific growth rate, feed efficiency, and protein efficiency ratio, significantly declined when FM replacement exceeded 40 %. Trypsin and lipase activity showed a linear decline with increasing CCM levels. Whole-body moisture content significantly increased, whereas crude protein content significantly decreased at 60 % FM replacement with CCM. Antioxidant enzyme activity and immune response markers declined at ≥ 50 % FM replacement. Although feed costs decreased with increasing CCM levels, economic conversion and profit indices were maximized at 40 % FM replacement. Broken-line regression analysis estimated the optimal FM-replacement level with CCM at 34.07 %. Overall, these findings suggest that up to 40 % of FM can be replaced with CCM in juvenile S. schlegelii diets without impairing growth, nutrient utilization, antioxidant function, or immune response, making it a cost-effective and sustainable alternative for aquafeeds.

Source: Aquaculture Reports

DOI: 10.1016/j.aqrep.2025.103312