Partial replacements of fishmeal by autoclaved shrimp processing by-product modulates the growth, digestive enzymes, immune-antioxidant, and economic performances for Nile tilapia (Oreochromis niloticus) juveniles

Abstract

In the current investigation, the fishmeal (FM) protein was substituted by shrimp processing by-product (SPB) protein in feeds for Nile tilapia ( Oreochromis niloticus ) juveniles. Six isonitrogenous and isocaloric feeds were designed to substitute the FM protein with graded levels of SPB protein, i.e., 0% (SPB0), 10% (SPB10), 20% (SPB20), 30% (SPB30), 40% (SPB40) and 50% (SPB50). Nile tilapia juveniles (13—15 g) were allocated into 18 100-L aquaria (15 fish per aquarium) and administered the evaluated feed three times daily until evident satiety for 90 days. It was detected that Nile tilapia given SPB diets exhibited enhanced ( P > 0.05) growth indices, especially at SPB40, compared to the control (SPB0). Related to the FM-based diet (SPB0), serum glucose and cortisol did not show substantial ( P > 0.05) changes; while, activities of alanine and aspartate aminotransferases were markedly ( P > 0.05) declined at SPB40 and SPB50 with no alterations between them. In comparison to the control diet (SPB0), SPB40-fed fish exhibited highest values of total protein, immune, and antioxidant biomarkers. The simple economic assessment suggested that incorporating 40% SPB instead of FM protein in O. niloticus diets represents the optimal choice, where it could reduce the feeding cost by 5.27% for ton fish gain. Interestingly, it is recommended to substitute 40% of FM protein with SPB in feeds for Nile tilapia, O. niloticus.

Bibliographic Information