The Ameliorative Role of Synbiotic Culture Techniques Application in White Shrimp (Litopenaeus vannamei) During Nursery Stage

The current study was conducted to analyze the potential benefits of dietary supplementation of synbiotics on water quality, microbial population, growth performance, proximate analysis, non-specific immune response, oxidative status, cytokine gene expression and susceptibility to experimental infection by V. harveyi in L. vannamei juveniles. A total number of 9000 white shrimp (L. vannamei) in post-larval stage (PL12) with mean initial weight (0.5 ± 0.02 g/ piece) obtained from Barket-Ghalioun fish farm, Kafr El-Sheikh Governorate were used. After the accommodation period, shrimps were randomly distributed into three experimental groups of 3000 post-larvae / each group allotted into three replicates of 1000 post-larvae / each replicate (experimental tanks). Salinity of all tanks was adjusted from 25‰ - 35‰. The first experimental group (G-I) was kept as control (feed on basal diets with continous change of water and aeration). The second experimental group (G-II) (synbiotic culture treatment) was fed on 50 % basal diets + fermented rice bran with Bacillus subtilis without change of water and high aeration). However, the last experimental group (G-III) was fed on fermented rice bran with Bacillus subtilis (without basal diets and change of water and high aeration). The synbiotic containing probiotic B. subtilis in shrimp diets could significantly improve the growth by enhancing the immune response, antioxidative activity, water quality and biofloc composition. The increase of nonspecific responses of the shrimp fed the synbiotic supplemented diets may suggest that the antioxidant defense system and innate immune system could work synergistically to improve the physiological performance of the shrimp leading to higher resistance against bacterial challenge. This system can play a key role in developing a sustainable aquaculture via better water quality, maintenance decrease in feed requirements and higher production to achieve more profit in shrimp farming. Consequently, the synbiotic could be practically used as a viable alternative dietary supplement.