Synergistic effects of combined probiotic supplementation on growth performance, survival, and health status in Labeo rohita

Abstract This study evaluated the effects of probiotic supplementation, including Saccharomyces cerevisiae (Sc), Bacillus subtilis (Bs), Bacillus licheniformis (Bl), and Trichoderma longibrachiatum (Tlb, Digest 54 Plus), on growth performance, hematological, and immunological parameters of Labeo rohita fingerlings. The fishes were divided into four groups, including three treatments receiving 0.25 g/kg, 0.50 g/kg, and 0.75 g/kg of probiotics, and a control group. After a 60-day trial, fingerlings provided with 0.75 g/kg probiotics showed significant improvements in growth performance, with a lower feed conversion ratio (1.47), higher specific growth rate, and protein efficiency ratio. Hematological analysis of these fingerlings revealed a significantly higher red blood cell count (3.47 × 10 6 cells/mm 3 ), elevated hemoglobin levels (90.1 ± 0.05 g/dL), and increased mean corpuscular hemoglobin concentration (22.87 ± 0.06 g/dL). Moreover, a 91% survival rate, as well as significantly higher serum lysozyme activity and total leukocyte count, was also recorded in the fishes supplemented with 0.75 g/kg probiotics. These findings suggest that combined probiotic supplementation (Sc, Bs, Bl, and Tlb, 0.75 g/kg, 30% CP feed) can enhance growth, immunity, and overall aquaculture productivity in Labeo rohita . Optimizing the application of probiotics in aquaculture would lead to more sustainable fish production systems, modernized aquaculture practices, and less consumption of chemicals.