The effect of isolated bacteria from the intestine of Beluga (Huso Huso) on some growth indices, amylase and lipase activity in body extract and carcass composition of the common carp (Cyprinus carpio) larvae

The aim of this study was to investigate the effect of probiotics isolated from the intestine of Beluga (Huso huso) fingerlings on growth factors, activity of digestive enzymes and carcass composition of common carp (Cyprinus carpio, Linnaeus 1758) larvae. Three hundred and sixty larvae with an average weight of approximately 200 mg after one-week adaptation to the new conditions, were fed with supplemented diets with blend of Bacillus subtilis, B. licheniformis and Saccharomyces cerevisiae in concentrations of 1.5 × 106 (T1), 3 × 106 (T2) and 4.5 × 106 (T3) CFU/100 g diet, respectively for 45 days. In control group, larvae were fed with diet without any supplementation. The experiment was carried out in a completely random design. At the end of the experiment, the results revealed that the highest final weight (35 ± 0.12 mg) and specific growth rate (0.94 ± 0.66%/day) were measured in T3. The highest feed conversion efficiency (46.52 ± 19.02%), protein efficiency ratio (0.37 ± 0.41), lipid efficiency ratio (1.22 ± 1.34), retained protein (0.0018 mg/day) and net protein utilization (0.0058%) were found in T3, while the lowest feed conversion ratio (2.34 ± 0.61) was obtained in T3. All of the above factors had significantly difference with control group (p<0.05). The maximum level of carcass crude protein (72.33 ± 0.68%) and crude lipid (13.43 ± 0.32%) were measured in T3. The  dry mater, crude energy and carcass ash levels did not exhibit significant differences in all the treatments compared to the control group (p>0.05). Amylase and lipase levels in the body extracts raised in the experimental treatments in comparison with the control group. However, only the amylase level displayed significant difference in comparison with control (p<0.05). The experiment indicated that the blend of Bacillus and yeast at different concentrations displayed different effects on carcass analyses and feeding indices in this fish and the best results were obtained in T3 (4.5 × 106 CFU/100g diet).