Assessment of hydrocare efficiency to reduce the total gastro-intestinal bacterial load of Beluga (Huso huso) fingerlings and rearing water

Objective: Hydrocare is a compound of hydrogen peroxide and sodium percarbonate that has disinfectant application. Method & Materials: In this research, 450 beluga fingerlings with 4.91291 gr mean weight and 10.9086 cm mean length were used. Fingerlings were kept in 9 veniros, in three replications of control group and treatments. First treatment was disinfected with 30 gr/m3 dosage, second treatment was disinfected with 40 gr/m3 dosage for 5 days (30 min) with Hydrocare. Physicochemical factors of water (temperature, Oxygen, Oxygen saturation percent, pH, Co2, No3, NH4, total hardness) were measured before and after using the disinfectant. Samples were washed three times with sterile neutral 0.9% salt solution (NSS) to remove no adherent bacteria. Then, gut was separated , washed with NSS and opened. Gut contents were washed 3 times with NSS, then homogenized together with NSS. Homogenates were diluted in NSS and 0.1 ml volumes of appropriate dilutions were spread on the surface of TSA (tryptic soy agar). The Plates were incubated at 20’c for 48-72 hours. For bacterial loading in rearing water, above process was done by the same method. After bacterial growth, CFU ( Colony Forming Unit ) was measured by counting. Results & Conclusion: Results showed that the mean of gut aerobic bacterial flora in the first treatment was 5.53±0.24 log cfu/gr and in the second treatment was 5.12±0.22 log cfu/gr, and they had a lower amount in comparing with control group with the mean of 6.45 ±0.33 log cfu/gr. According to One way ANOVA and Tukey HSD examination the results showed significant statistical difference (p<0/05) and bacterial load had a higher amount in Control group. In the study of rearing water, the mean of aerobic bacterial flora of rearing water in the first treatment was 4.62 ± 0.11 log cfu/ml and in the second treatment was 3.98 ±0.43 log cfu/ml and they had a lower amount compare to control group with the mean of 5.28 ±0.96 log cfu/ml. According to One way ANOVA and LSD examination a significant statistical difference was observed (p<0/05) .and bacterial load has a higher amount in Control group.

Keywords:

Huso huso , Hydrocare , Hydrogen peroxide , Bacterial load , Fingerlings