Figure 1. Isotopic values (δ¹⁵N; ‰) of rainbow trout (Oncorhynchus mykiss) muscle tissue that were isotopically equilibrated into four experimental diets with different levels of substitution of fishmeal with poultry by-product meal (time 0) and were then switched to the control diet and fed for a 28 additional days.

PBM: Poultry by product meal. Values shown are means (n = 3) ±SD.