Mathew cautions, however, that the preliminary results may be misleading and that resistant bacteria are also found on organic farms. Mathew's other grant supports research on determining the effects of various antibiotic dosing schemes. Techniques such as pulse dosing, increased dose concentration, and antibiotic rotation were studied to determine how they affect animal health and performance and antibiotic resistance of bacteria associated with swine. Dr. Richard Strange is doing in one of his current projects. Working in aquaculture facilities of the Johnson research facility, Strange is trying to determine the effects of feeding salt-enriched diets to rainbow trout.
Rainbow trout are an essential commodity in Tennessee aquaculture.
Strange notes that reducing the occurrence of brown blood disease and stress-induced hemodilution will have broad application in the aquaculture industry. Hemodilution is a loss of blood electrolytes in cultured fish resulting from stress. Handling, grading, and transporting the fish are often the source of this stress. Past research suggests that fish dying because of transport stress are actually dying because of hemodilution. Studies indicate that mortality is low when transferring certain fish to salt water if they dine on a salt-enriched fare, because the salt increases not only the resting levels of blood plasma electrolytes but also the size and number of chloride cells in the gills.