Introduction: This study was conducted to monitor and evaluate the effective environmental and administrative risk factors in the occurrence of some specific viral diseases in the rainbow trout production of specific pathogens free (SPF) in Tonekabon city.
Materials & Methods: For this purpose, physical, chemical, and microbial factors of input and output water of the farm, such as dissolved oxygen, temperature, pH, nitrite, nitrate, ammonium, ammonia, and total bacteria count for six months from May to Oct 2017 were measured according to the standard method. Further, the fish were sampled to check for the possibility of infection with IPN, IHN, and VHS viruses. The investigated farm had two separate input and output water, a river and a spring and stream.
Results: Mean temperature, dissolved oxygen, pH, nitrite, nitrate, ammonium, ammonia, and total bacteria count of river input water were 15.86±1.14 C°, 8.98±0.28 mg/L, 8.36±0.26, 0.02±0.02 mg/L, 1.42±0.2 mg/L, 0.04±0.03 mg/L, 0.03±0.03 mg/L and 221.17 colony unit per mL, respectively, and river output water were 16.27±0.97 C°, 8.72±0.27 mg/L, 8.26±0.18, 0.03±0.02 mg/L, 1.88±0.36 mg/L, 0.14±0.1 mg/L, 0.14±0.1 mg/L, and 411.17 colony unit per mL, respectively. Further, mean temperature, dissolved oxygen, pH, nitrite, nitrate, ammonium, ammonia, and total bacteria count of spring and stream input water were 16.5±0.73 C°, 8.82±0.19 mg/L, 8.14±0.19, 0.02±0.02 mg/L, 2.6±0.83 mg/L, 0.13±0.12 mg/L, 0.13±0.11 mg/L and 68.67 colony unit per mL, respectively, and spring and stream output water were 16.08±1.01 C°, 8.7±0.21 mg/L, 8.15±0.26, 0.03±0.02 mg/L, 3.07±0.67 mg/L, 0.21±0.18 mg/L, 0.2±0.17 mg/L, and 186 colony unit per mL, respectively. According to the obtained data, temperature, pH, ammonia amounts, and total bacteria count were assessed as risk factors in the river water of the farm, and temperature, pH, and ammonia amounts were evaluated as risk factors in the spring and stream water of the farm. In Addition, virology experiments showed that the cultured fish were not infected by IPN, IHN, and VHS viruses.
Conclusion: Overall, environmental and management parameters in the selected farm in Tonekabon City, Mazandaran province of Iran were assessed as suitable and acceptable for the culture of rainbow trout Specific Pathogens Free (SPF). |
