Effect of probiotics on growth performance and digestive enzyme activity of the shrimp Penaeus vannamei

The effect of probiotics on growth performance and digestive enzyme activity of the shrimp Penaeus vannamei was investigated. Photosynthetic bacteria and Bacillus sp. were added to shrimp basal diets as probiotics at three concentrations: T-1, 2 g kg− 1 (1 g kg− 1 lyophilized photosynthetic bacteria cells (PSB) and 1 g kg− 1 lyophilized Bacillus sp. (BS)); T-2, 10 g kg− 1 (5 g kg− 1 PSB and 5 g kg− 1 BS); and T-3, 20 g kg− 1 (10 g kg− 1 PSB and 10 g kg− 1 BS). Twelve aquaria with three replicates for each treatment group and the Control group were used. After 28 days, shrimp receiving the diets supplemented with probiotics showed significantly better growth performance than those fed the basal diet (Control). The mean digestive enzyme activity of each treatment groups was significantly different (P < 0.05) from that of the Control. The protease activity of T-2 and T-3 was significantly higher compared with T-1 and the Control. However, there was no significant difference between T-2 and T-3. The amylase activity of T-2 was highest and significantly different (P < 0.05) from that of the Control and T-1. Both treatment groups had significantly higher lipase and cellulase activity compared to the Control.