Effect of Water Soluble Polysaccharide Extract of the Algae, Padina australis Hauck, on the Activity of Digestive Enzymes and Biochemical Parameters of White-leg Shrimp, Litopenaeus vannamei

In the present study, the water soluble polysaccharide extract of Padina australis (PPE) was added in concentrations of 0, 0.5, 1 and 1.5 g/kg to the diet of white leg shrimps (Litopenaeus vannamei) with average weight of 1±0.1 g to assess its ability to improve the activity of digestive enzymes and the biochemical parameters. Following feeding on these diets for 60 days, the highest activity of lipase and protease was shown in treatment containing 1.5 g PPE/kg diet (p < 0.05). The levels of albumin and total protein were higher in treatments containing various levels of PPE compared to the control treatment (p < 0.05). The lowest levels of GLU, TRI, CHO, ASP.ALT and ALP were observed in the treatment containing 1.5 g PPE/kg diet indicating significant difference with other treatments (p < 0.05). The results demonstrated that inclusion of 1.5 g/kg diet of PPE in commercial feeds might enhance the digestion function, liver health and nonspecific immunity system of L. vannamei.