Oral supplementation of low alginate dose in diet stimulates immune response of Litopenaeus vannamei at concrete circle pond mass culture

Abstract

Abstract Litopenaeus vannamei is popular due to its ability to grow in different scales of rearing as a valuable export product. This research aimed to define the impact of alginate diet supplementation in a low dose as an immunostimulant strengthens the non-specific immunity of shrimps. The study was conducted in 20 tons concrete circle ponds with two treatments at the density of 400 ind.m-2. First, there were control A and B, and secondly, there was the addition of 1.0 g alginate in 1.0 kg of feed namely alginate 1.0 g kg-1 (A and B). Shrimps were reared for 30 days, and the non-specific immune parameters were assessed on 22 and 30 days of rearing. The parameters covered in this study were THC (total count of hemocyte), PA (activity of phagocytosis), PI (index of phagocytosis), PO (phenol-oxidase), SOD (superoxide dismutase), and LYZ (lysozyme) activity. Results showed that the THC/PA/PO, and LYZ enzyme activity of sodium alginate treatments were higher than the control (p<0.05), though the PI, SOD, and weight gain at the end of the experiment have not shown any differences. It is concluded that the supplementation of alginate at 1.0 g kg-1 enables to increase in the shrimps’ immune system and this application is projected to be useful in terms of blocking out the large-scale application of immunostimulants in ponds.