Influence of extremely low frequency electromagnetic fields on growth performance, innate immune response, biochemical parameters and disease resistance in rainbow trout, Oncorhynchus mykiss

摘要

The effects of extremely low frequency electromagnetic fields on rainbow trout growth performance, innate immunity and biochemical parameters were studied. Rainbow trout (17-18 g) were exposed to electromagnetic fields (15 Hz) at 0.01, 0.1, 0.5, 5 and 50 mu T, for 1 h daily over period of 60 days. Growth performance of fish improved in different treatment groups, especially at 0.1, 0.5, 5 and 50 mu T. Immunological parameters, specifically hemagglutinating titer, total antiprotease and alpha(1)-antiprotease levels in treatment groups, were also enhanced. Total protein and globulin contents in the serum of fish exposed to 0.1, 0.5, 5 and 50 mu T were significantly higher than those in the control group. No significant differences were found in serum enzyme activities, namely aspartate aminotransferase and alanine aminotransferase of fish in all treatment groups. Conversely, alkaline phosphatase level decreased in fish exposed to 0.01 and 50 mu T electromagnetic fields. Meanwhile, electromagnetic induction at 0.1, 0.5, 5 and 50 mu T enhanced fish protection against Yersinia ruckeri. These results indicated that these specific electromagnetic fields had possible effects on growth performance, nonspecific immunity and disease resistance of rainbow trout.