Serum Protein Profile of Juvenile Pacu (Piaractus mesopotamicus) and Dourado (Salminus brasiliensis) Fed Bovine Colostrum as Partial Source of Protein in the Diet

Abstract

Objective: The electrophoretic profile of serum proteins was investigated in juvenile Piaractus mesopotamicus and Salminus brasiliensis fed with diets containing bovine colostrum, a nutraceutical food, in lyophilized form (LBC) for either 30 or 60 days. Materials and Methods: Blood samples were collected from juveniles of P. mesopotamicus and S. brasiliensis fed for either 30 or 60 days with diets containing 0%, 10% or 20% of LBC. Serum protein fractions were then determined by electrophoresis in agarose gel. Results: The P. mesopotamicus, an omnivorous fish, showed six serum protein fractions, while the S. brasiliensis, a carnivorous fish, showed four serum protein fractions. In both species the albumin fraction showed higher protein content at 30 days than at 60 days (p<0.05), indicating an inverse relationship with growth. The 5th and 4th fraction in mobility from the P. mesopotamicus and S. brasiliensis serum, respectively, were positioned in a gamma-globulin zone. In P. mesopotamicus, the concentration of protein in the gamma-globulin zone was higher at 60 days than at 30 days (p<0.05). In S. brasiliensis, in turn, the concentration of protein in the gamma-globulin zone was higher at 30 days than at 60 days (p<0.05). In juvenile P. mesopotamicus, a higher concentration of protein was also observed in the gamma-globulin zone in the 0% LBC compared to 10% and 20% LBC (p<0.05). Thus, the feeding period influenced only the fractions that were positioned in the albumin and gamma-globulin migration zone in both species. Conclusion: The consumption of bovine colostrum decreased the concentration of protein in gamma-globulin fraction of the P. mesopotamicus, indicating that these juveniles had either less stimulus for their own synthesis of defense elements or an immunosuppressive effect of bovine colostrum ingestion.