This study was performed to assess the effects of three levels of EM4 probiotic on water quality, growth and feed utilization in Cyprinus carpio. Four experimental group were tested: P1, control group, artificial feed without probiotics; P2, probiotics at 5 ml kg-1 artificial feed; P3, probiotics at 10 ml kg-1 artificial feed; and P4, probiotics at 20 ml kg-1 artificial feed. Daily water change was 5%. Fish were fed 32% protein COMFEED SPLA 12 feed three times daily at 3% of body weight for 60 days. NH3 and NO2 decreased significantly (p ≤ 0,05) in probiotics treated groups, especially P4, compared with the control. Water quality, growth, and feed utilization increased significantly (p ≤ 0,05) in probiotics-treated groups, especially P4, compared with the control. On the survival rate, there was no significant effect due to the influence of probiotics (p ≥ 0,05). This study confirms the importance of probiotics as a fed to improve water quality, growth and feed utilization of Cyprinus carpio.
The application of EM4 probiotics in artificial feed significantly (p ≤ 0.05) improved water quality parameters in all probiotics-treated groups compared with the control group (Table 1). The lowest NH3 and NO2 values were found in group P4. The control group showed higher levels of NH3 and NO2. Probiotics the treatment group showed a decrease in the ratio of NH3 and NO2 values compared to the control group.
The growth and feed utilization of Cyprinus carpio fed different levels of EM4 probiotics are given in Table 2. Final weight, daily weight gain, specific growth rate, and condition factor increased significantly (p ≤ 0.05) with the increased in probiotics levels. While, there were not significantly different from these parameters in probiotics 5 ml kg-1 and 10 ml kg-1. The highest growth was obtained at probiotics level 20 ml kg-1 (P4 group), whereas the control group produced the lowest growth. The application of probiotics in level 20 ml kg-1 (P4) achieved the best significant results (p ≤ 0.05) FCR and feed efficiency values compared with the other treatments (Table 2).