Application of multi-species of bacillus in Rainbow trout (Oncorhynchus mykiss) larvae nutrition via Bio-enrichment of Artemia parthenogenetica nauplii

In order to reveal the potential of probiotic Bacilli and their promoted effects on growth and survival rate of rainbow trout (Oncorhynchus mykiss) larvae, a 30-day feeding experiment was conducted in rainbow trout larvae by feeding of bio-enriched Artemia parthenogenetica nauplii in suspension of five probiotic bacillus at doses of 0, 1×108, 2×108 and 3×108)CFU/liter(of broth. After a 30-day feeding experimental period, all of the the trout larvae in each tank were sampled for biometry and growth determination. The Results showed that, with inoculating probiotic Bacilli in suspension of broth, trout larvae survival and growth parameters generally increased. Fish larvae fed with enriched Artemia nauplii at dose of 2×108 CFU/L in suspension of broth, had significantly higher survival and growth parameters than the control group (P0.05). The probiotic bacillus had significant positive effects on the Specific Growth Rate (SGR), Thermal growth coefficient (TGC), Feed Conversion Efficiency (FCE) and Relative gain rate (RGR) in comparison with control treatment (P0.05). Then, our results confirm the potential of multi-species of probiotic Bacillus had promoted effects on enhancement of survival rate and growth performance of Rainbow trout larvae