Replacement of Menhaden Fish Meal by Poultry By-Product Meal in the Diet of Juvenile Red Porgy

Poultry by-product meal (PBM) was tested as a substitute for fish meal (FM) in the diet of juvenile Red Porgy Pagrus pagrus. Eight diets (50% crude protein, 13% crude lipid) were formulated to replace FM protein with PBM protein at 0 (control), 10, 20, 30, 40, 50, 60, and 70%. Juvenile Red Porgy were fed the diets twice daily to apparent satiation for 8 weeks. Fish were held in 75-L rectangular tanks with 15 fish/tank using a recirculating seawater (34 g/L) system maintained at 22 degrees C. No significant differences in body weight gain (BWG; 318-387%), final weight (17.4-20.4 g), specific growth rate (2.55-2.77% per day), feed conversion ratio (0.85-1.18), protein efficiency ratio (0.45-0.61), or survival (84-98%) were observed among fish fed diets replacing 0-70% of FM protein with PBM protein. After the feeding trial, the survival, growth, feed utilization, fish whole-body protein, lipid, docosahexaenoic acid content, and apparent digestibility of protein were not significantly different for fish fed diets with up to 70% of FM protein replaced by PBM compared to a 100% FM-protein-based control diet. Broken-line regression analysis with BWG indicated that PBM protein can replace FM protein in Red Porgy diets at levels as high as 54.0% with no reduction in fish growth performance. Poultry by-product meal is a cheaper and more sustainable ingredient than FM and is an excellent alternative protein source for Red Porgy.