Effects of heat-killed Lactobacillus plantarum strain L-137 on growth performance and immune responses of white leg shrimp (Litopenaeus vannamei) via dietary administration

Abstract

Cultivation of white leg shrimp Litopenaeus vannamei has been faced to unprecedented disease and environmental issues. This study was conducted to determine the effect of heat-killed Lactobacillus plantarum strain L-137 (HK L-137) on growth performance and immune responses of L. vannamei via dietary treatment. Different levels of 20% HK L-137 (LP20) were added into a commercial feed including 0.0g of LP20 kg-1 of feed (control), 0.1g of LP20 kg⁻¹, 0.05g LP20 + 5g β-glucan kg⁻¹ and 10g β-glucan kg⁻¹. Shrimp (PL12) were fed with these feeds for 90 days in re-circulation 2 m3 tanks at stocking density of 300 ind./tank. The results showed that survival and growth rates of shrimp fed with feed supplemental LP20 were significantly (P<0.05) higher compared to other feeds. Immune parameters consist of total haemocyte count, differential haemocyte count, phenoloxidase activity, phagocytic activity and clearance efficiency, Vibrio parahemolyticus challenges were increased significantly (P<0.05) for those animals fed with HK L-137. This study demonstrated that HK L-137 would enhanced growth performance and improved immune defense system of L. vannamei.