Antioxidant status and Immune parameters in selected tissues and hemolymph of Pacific white shrimp LitoPenaeus vannamei during different feeding Trails

The present investigation evaluated the immunological and antioxidant responses of LitoPenaeus vannamei subjected to dietary supplementation with Probiotics (PB), Bioflocs (BF), and their combination (PB+BF) during shrimp culture operations. The study assessed key hemolymph immune parameters including Total Haemocyte Count (THC), Hyalinocytes (HC), Semi-granulocytes (SGC), and Granulocytes (GC) at different culture stages (0, 40, and 80 Days of Culture-DOC), alongside antioxidant enzyme activities such as Superoxide Dismutase (SOD), Catalase (CAT), Glutathione Peroxidase (GPx), and Glutathione S-transferase (GST) in hepatopancreas, gill, and haemolymph tissues.Results indicated a significant enhancement of THC and its sub-populations in shrimp fed with PB, BF, and particularly PB+BF, compared to the control. Phenoloxidase (PO) activity also increased significantly, suggesting an elevated immune readiness and microbial clearance potential. Concurrently, elevated antioxidant enzyme activities across tissues were observed, particularly in PB and BF-fed groups, indicating a strong response to reactive oxygen species (ROS) and oxidative stress, likely induced by microbial presence and hypoxic conditions. Increased malondialdehyde (MDA) levels, especially in hepatopancreas and haemolymph, confirmed oxidative stress occurrence, while enhanced antioxidant responses suggested efficient cellular protection and recovery.These findings confirm that dietary supplementation with Probiotics and Bioflocs enhances immune competence, antioxidant capacity, and bacterial clearance in L. vannamei, ultimately contributing to improved growth performance, feed utilization, and disease resistance. The synergistic application of PB+BF offers a promising approach for sustainable and resilient shrimp aquaculture practices.