Spray-dried porcine plasma (SDPP) is a protein-rich blood by-product obtained from abattoirs. It contains diverse biological components including immunoglobulins (Ig), albumin, peptides, enzymes, and growth factors. As a protein source, SDPP has been reported to promote the health of animals including pigs, chickens, and fish. Nevertheless, the effect of SDPP on shrimp health is less known. The aim of the current study was to investigate the health-promoting effects of SDPP in the diets of Pacific white shrimp.
Postlarvae-12 shrimp were randomly distributed into 20 fiberglass tanks with 200 L of water (27-29°C and 25 ppt salinity) with a stocking density of 80 shrimp/tank. Five experimental diets were formulated with different concentrations of SDP (AP 820, APC Europe, Granollers, Spain): control, SDPP at 1.5, 3, 4.5, and 6% diet. These experimental diets were fed to the shrimp 4 times/day. On day 45, five shrimp from each group were randomly selected for the immunological study which consists of total hemocyte count and phenoloxidase activity, whereas all survived shrimp were challenged with Vibrio parahaemolyticus by immersion method at the concentration of 105 CFU/mL for another 4 days. The shrimp body weight and mortality rate of each group were recorded at the end of the feeding trial.
Our result demonstrated that the immune parameters of the shrimp fed on 3-6% SDPP were significantly (p<0.05) improved compared to the control and 1.5% SDPP groups (Table 1). At 4 days after being challenged with V. parahaemolyticus, the mortality rate of the 3-6% SDPP groups was 52-55%, significantly (p<0.05) lower than that of the control shrimp (71%) (Table 2). The highest final body weight was observed in the 4.5 and 6% SDPP-fed shrimp which were 3.12 and 3.21 g, respectively, and significantly (p<0.05) different from the control (2.62 g) (Table 2).