Replacement of fish meal by poultry by-product meal, food grade, in diets for juvenile spotted rose snapper (Lutjanus guttatus)
The feasibility of replacing fish meal protein at different levels with poultry by product meal food grade (PBM-FG) was assessed in diets for spotted rose snapper Lutjanus guttatus. Four diets were formulated, the control diet fish meal was used as the main protein source (FM); the other three diets had increasing levels of PBM-FG replacing 25, 50 or 75% of the fish meal protein respectively. The diets were fed close to apparent satiation, three times a day to quadruplicate groups of juvenile snapper (average body weight 11.0 ± 0.04 g). The fish were randomly distributed into groups of 15 fish in a 120 L seawater tank. The response of snapper to diets containing graded levels of fish meal was evaluated by measuring weight gain, feed efficiency, body composition, hematological parameters and apparent nutrient digestibility during a 12-week period. The replacing of the 25% of fish meal protein by PBM-FG did show a similar trend for feed efficiency and growth performance than control diet. Feed efficiency and growth performance was reduced at 75% level of fish meal protein replacement by PBM-FG, due to deficiencies of lysine and methionine. The final whole-body proximate composition did not differ among treatments. The hematological characteristics were similar among the treatments control, 25 and 50%, but the fish fed PBM-FG 75% showed the lowest levels for total protein and glucose parameters. The dietary dry matter and protein apparent digestibility coefficients (ADCs) decreased with increasing dietary PBM-FG. High values for lipid ADCs were observed in all diets.