The potential of probiotic bacilli on the growth and feeding performance of Rutilus rutilus larvae

The 5 species of endospore bacillus, B. licheniformisi, B. subtilis, B. polymyxa, B. laterosporus and B. circulans, were prepared from Protexin Co. This experiment was conducted in a completely randomized design with four treatments (trial 1-3 and control) with three replicates for treatment and control. The spores of bacteria were grown in their special media and in 37°C for 8 h. Five isocaloric and isonitrogenous diets (D1-D4 and RD) were prepared containing similar ingredient composition. Experimental diets (D1-D4) were supplemented with the probiotic bacillus at four different levels of 1×108 (diet D1), 2×108(diet D2), 3×108(diet D3), 4×108(diet D4) bacteria cells (CFU) per g and control diet (without probiotic bacillus) were prepared. The Rutilus rutilus brood stocks were preparation and their larvae were used in our study. The feeding trial was conducted by 15 circular fiberglass tanks. The initial body weight of Rutilus rutilus larvae was 326.0765.21 mg. Fifty acclimated fish were randomly allocated into each of fifteen circular fiberglass tanks (13L). The Rutilus rutilus larvae were fed on the base of the 10 percent of their body weight for 4 times per day for a period of 45 days. The control treatment was fed on unbacterial supplemented diet. In the termination of experiment, all fish were sampled and measured of their total length, body weight. The growth and feeding performance was calculated by using of mathematical model. Final weight, total lenght and SGR, CF, PER and LER of Rutilus rutilus larvae, were affected by bacterial supplemented diet in experimental treatments. The maximum body weight (514.17 mg) was obtained in treatment of diet D3 (3×108 CFU/kg). The positive significant correlation was obtained between the concentration of bacillus in experimental diets and body weight gain. The beter PER and LER were obtained in experimental treatments of D2, D3 and D4

کلیدواژه ها:

endospore bacillus ، Rutilus rutilus ، experimental diets ، feeding performance ، SGR