Evaluation of commercial probiotics for growth, health, and biometric indices of Thai silver barb (Barbonymus gonionotus)

This study evaluated the effects of commercial probiotic supplementation on growth performance, feed utilization, water quality parameters, blood parameters, intestinal morphology, gut bacterial load, and biometric indices of the Thai silver barb (Barbonymus gonionotus). A total of 5,250 healthy juveniles (2.67 ± 0.03 - 2.74 ± 0.02 g) were randomly divided into five groups, each with three replications (350 fish/pond), and fed for 90 days. Treatments included a basal diet supplemented with gut probiotic ZYMETIN (T₁), water probiotic POND CARE (T₂), soil probiotic Super PS (T₃), a combination of all three at half doses (T₄), and a control (T₅) with no probiotics. Results showed a significant (P < 0.05) improvement across probiotic-treated groups compared to T₅, with T₁ (gut probiotic) yielding across probiotic-treated groups compared to T₅, with T₁ (gut probiotic) achieving ~ 133% greater net weight gain and ~ 128% higher RGR than the control. Particularly, water quality revealed substantial variations in pH and ammonia (NH₃), with the highest pH in T₁ and the highest ammonia found in T₃. Gut bacterial load increased notably in probiotic-treated groups, with T₁ showing the highest count at the end. Histological analysis revealed improved intestinal morphology in probiotic-treated groups. Hematological parameters showed noticeable differences in blood parameters, with T₁ exhibiting the highest WBC and RBC counts and the lowest MCH levels. Principal Component and Cluster Analyses confirmed strong correlations between growth, feed utilization, and hematological parameters. Overall, the findings suggest the potential of probiotics as an eco-friendly approach to enhance B. gonionotus aquaculture.