Vol. 9, Special Issue 1, Part K (2025)

A feeding trial was conducted to study the dietary effect of feeding probiotics on growth performance and gut microbial changes of fish, Silver barb (Puntius gonionotus) yearlings for 90 days. Four iso-nitogenous diets (crude protein: 32%) with graded levels of probiotics incorporation i.e. T₁(Control), T₂ (Lacto Bacillus sporogenes at a rate of4% in the diet), T₃ (Saccharomyces cerevisiae at a rate of 4% in the diet) and T₄ (L. sporogenes + S. cerevisiae at a rate of 2% each in the diet) were fed to Silver barb yearlings (average body weight: 63.42±1.13 g to 64.42 ± 0.66 g) in triplicates (12 healthy fish per replicate) following a completely randomised design (CRD). Twelve FRP tanks of 500-L capacity having a provision of aeration were used for rearing the fish. Fishes were fed with the diets at the rate of 3% of their body weight twice daily. The average bodyweight gains (%) of fish were 30.55±3.40, 40.64±1.83, 55.91±3.29 and 73.07±1.72 for T₁, T₂, T₃, and T₄, respectivelyat the end of the study. Highest growth as measured by average final weight (110.31±1.58 g), body weight gain (46.58±1.30 g), SGR (0.61±0.01% per day), PER (1.35±0.04) coupled minimum FCR (2.75±0.09) was observed in T₄ group compared to other groups (p<0.05). Moreover, the T₂(21366.67± 185.59) and T₄(232333.33± 6661.92) treatments showed significantly higher in gut microbial count i.e., L. sporogenes and S. cerevisiae, respectively followed by T₄ treatment in L. sporogenes (12100.00±152.75) and T₃ treatment in S. cerevisiae (198333.33±1201.85).In line to this, data on gut S. cerevisiae count was reported significantly higher in T₄ treatment throughout the study than in others (p<0.05).The findings from the study also revealed that the probiotic bacteria i.e. S cereviciae was colonised in the gut after 15 days, however, L. sporogenes was not colonized in the gut. In conclusion, the study revealed the feasibility of dietary incorporation of both probiotics i.e. L. sporogenes and S. cerevisiae in the diets of Silver barb at the rate of 4% (2% each) for better growth and optimum gut microbial flora.