Juvenile of Yellowtail, Seriola dorsalis fed diets from partial to total fish oil and fish meal replacement

Abstract

This study aimed to evaluate the effect of partial to total replacement of fish meal (FM) and fish oil (FO) from diets formulated for the yellowtail (Seriola dorsalis) using poultry by-product meal (PBM) as the main protein source, beef tallow as the main fat source, and supplemented with microalgae oil from Schizochytrium sp. Four experimental diets were formulated to be isoproteic (45.0 % crude protein) and isolipidic (12.0 % crude fat), based on the yellowtail nutritional requirements. Cholesterol was added to compensate its content in the FO. Lysine and methionine were also added to compensate its lower amount in the PBM. DHA-Nature™ was additional incorporated to reach similar levels of DHA than those present in FM and FO. One hundred and eighty S. dorsalis juveniles (14.54 g ± 0.19 g, mean ± SE) were randomly distributed into 12 tanks with 500 L each, connected into a recirculation system. After 48 days experimentation procedure, no significant differences were observed in performance. It is concluded that PBM can efficiently replace FM and FO in diets for Seriola dorsalis without any negative impact, where the fatty acid combination contained in the total replacement favored the use of fat as an energy source if DHA is enriched. However, it will be interesting to study the gene expression within the growth axis to fully comprehend the role of somatic growth vs. growth in length.

Keywords

• fish-free
• sustainability
• nutrition
• feeds
• aquaculture
• alimento libre de pescado
• sustentabilidad
• nutrición
• alimentos
• acuicultura