Fish meal (FM) is a protein source commonly used in feeds for atlantic salmon (Salmo salar), but it is gradually becoming a more expensive and less sustainable resource. The use of alternative plant-based protein sources, especially from soy, as partial replacement for FM is currently common practice but limited due to the presence of antinutrients that negatively affect function and health of the gut of fish. Palbio 50 (Bioiberica SAU, Barcelona, Spain) is a high-quality protein source obtained from porcine intestinal mucosa as byproduct of the heparin manufacturing process, which makes it very sustainable. Palbio 50 is also a source of bioactive peptides. Its inclusion in diets for salmon could allow lower inclusion levels of plant-based protein sources, hence sparing their associated undesired effects, as well as providing economic savings. The objective of the present study was to evaluate the effects of partially replacing FM by Palbio50 on diet costs and performance parameters in salmon which are fed plant-based protein sources as alternative to FM.
Fish were allocated in 1000-L tanks and received different diets (in triplicate) as shown in Fig. 1. All diets used in the study were formulated so that they were isoprotein, isoelectrolytic and isoenergetic. In our study, including Palbio 50 allowed lower diet costs, compared to the control commercial diet. After 90 days, fish experienced a significant weight increase (863 vs 228 g; p=0.0091). Replacing FM by Palbio 50 did not affect fish performance, as there were no significant differences (p>0.05) between groups in weight, SGR, GF3, FCR and SFR (Fig. 2). No significant changes in water temperature or oxygen saturation occurred (around 12.5 ºC and 99.5 %).
In conclusion, the use of Palbio 50 in salmon diets, as partial replacement of fish meal, allows a reduction in the diet cost and leads to non-inferiority in terms of performance. Therefore, Palbio50 represents a more sustainable and inexpensive alternative protein source to FM without affecting the adequate performance of fish.