Effect of metalloprotein on growth, survival and non-specific immunity of pacific white shrimp (Litopenaeus vannamei)

Effects of metalloprotein on growth, survival and immune response in Pacific white shrimp (Litopenaeus vannamei) was conducted under laboratory conditions. The experiment was carried out in three treatments (with three replicates/treatment). Each replicate was consisted of 30 shrimp (7.5+-0.5 g) and rearing for the period of 55 days. Treatment 1 or control group, shrimp were fed with pelleted feed containing graded levels of normal feed with normal oxygen conditions (5.9-7.8 ppm). Treatment 2, 1 g metalloprotein/kg of the feed was added and rearing in low oxygen conditions (3.0-4.1 ppm). Treatment 3, shrimp were fed with normal feed without metalloprotein also in low oxygen conditions. After 55 days of dietary administration. shrimp fed with normal feed with normal oxygen conditions had an average body weight (15.00+-1.36 g) which was significantly higher (P LT 0.05) than shrimp fed with 1g metalloprotein/kg of the feed in low oxygen conditions (12.11+-1.13 g) and the group that fed with normal feed in low oxygen conditions(12.00+-2.85 g) respectively. Survival rate of shrimp was higher (P GT 0.05) in the group that fed with normal feed in normal oxygen conditions (93.33+-3.33 percent) than that shrimp fed with 1g metalloprotein/kg of the feed in low oxygen conditions (61.11+-1.92 percent) and normal feed in low oxygen conditions (45.56+-3.85 percent) (P LT 0.05) respectively. However, shrimp fed with 1 g metalloprotein/kg of the feed had significantly higher survival rate than the control group without metalloprotein (P LT 0.05). The immune characteristics of Pacific white shrimp in this study revealed that number of total hemocyte (THC), percentage phagocytosis, phenoloxidase activity and superoxide dismutase activity of shrimp from control group and shrimp fed 1 g metalloprotein/kg of the feed in low oxygen conditions were not significantly different (P GT 0.05) but higher than treatment group without metalloprotein (P LT 0.05). The present study indicate that oral administration of metalloprotein could increase immune response and survival rate of L. vannamei in low oxygen conditions.