Field Testing of Dual-species Synbiotic Microcapsules during IMNV Disease Outbreak and Fluctuate Weather: Growth Performance and Immune Response in Vaname Shrimps

Abstract

This study aimed to evaluate the effectiveness of synbiotic microcapsules through feed on growth performance and immune response of vaname shrimp in field testing during IMNV disease outbreak and fluctuate weather. Four groups of shrimp(4.11±0.05g) were fed with different doses of synbiotic microcapsules, SIN 0(0%), SIN 0.5(0.5%), SIN 1(1%) and SIN 1.5(1.5%) for 60 days. The synbiotic microcapsules consisted of prebiotic mannanoligosaccharide/MOS, probiotic Pseudoalteromonas piscisida (1UB) and Bacillus cereus (BR2). This study focused on growth performance (survival rate/SR, specific growth rate/SGR, feed conversion ratio/FCR), immune response (total hemocyte count/THC, differential hemocyte count/DHC, respiratory burst/RB, phenoloxidase/PO activity, phagocytic activity/PA), microbiology (total bacterial count/TBC, 1UB+BR2 TetR count, total Vibrio count/TVC) and histopathology. The results showed significant results that synbiotic microcapsules increased SR, SGR also reduced FCR with the best results in SIN 1.5 (SR: 93.50±1.30%. SGR:4.83±0.01% days-1 and FCR:1.16±0.02). Immune response of THC, RB, PO and PA in the synbiotic microcapsule treatment showed higher values with the best results in SIN 1.5 treatment while DHC had no significant difference. The values of TBC, 1UB and BR2 TetR count increased until the 60th day with the highest value in the SIN 1.5 while TVC showed the lowest value in both intestinal and hepatopancreas organs. Histopathological results showed hepatopancreas and intestinal organs experienced tissue damage in all treatments with synbiotic microcapsules showing less damage when compared to SIN 0. In conclusion, supplementation of synbiotic microcapsules through feed can improve growth performance, immune response and suppress Vibrio during outbreak with the best dose of 1.5%.