Effects of varying dietary black garlic supplementation on the growth, immune response, digestive and antioxidant activities, intestinal microbiota of Litopenaeus vannamei and its resistance to Vibrio parahaemolyticus infection

Abstract

A 56-day feeding try was conducted to evaluate the effects of processed garlic known as black garlic (BG) fed at different inclusion levels (0 (BG0, control), 5 (BG0.5), 10 (BG1), 20 (BG2), 40 (BG4), and 80 (BG8) g/kg feed) on the growth, whole body composition, immune and antioxidant enzyme activities, gut microbiota and resistance to Vibrio parahaemolyticus infections in Litopenaeus vannamei (initial weight = 0.60 ± 0.001 g). The results revealed a significant improvement (p < .05) in the final weight, weight gain rate, specific growth weight, condition factor, protein efficiency ratio, survival rate, hepatosomatic index, and feed conversion ratio in the BG-treated-groups compared to the untreated. Correspondingly, the whole body proximate composition, immune, and antioxidant enzyme activities significantly improved in the treated groups than the untreated. Dietary BG had shaped the gut microbiota by significantly increasing (p < .05) the abundance of Phylobacterium, Ruegeria, and Pseudoalteromonas genera and decreasing (p < .05) the abundance of Vibrio genus than the control. Disease test with V. parahaemolyticus revealed significantly high (p < .05) resistance in the BG-teated-groups than the untreated. The BG8, BG4, BG2, BG1, and BG0.5-treated groups respectively showed 72.1%, 62.8%, 55.8%, 41.9%, and 25.6% relative percentage survival. Dietary BG inclusion at 8% or at 80 g/kg feed could help improve shrimp growth and health.