Effect of Garlic extract (Allium sativa) and purple Coneflower (Echinacea purpurea) on hematological parameters and resistance to bacterial infection in rainbow trout (Oncorhynchus mykiss)

Blood tissue is an important indicator of the physiological condition of the body's organs to diagnose disease and organisms biological control, as aquatic animals. This study aimed to determine the factors and parameters hematological including white blood cells, hemoglobin, hematocrit and percentage differential white blood cell such as neutrophils, lymphocytes and eosinophils with garlic extracts and Echinacea extracts on rainbow trout was impressed. 1050 fishes with an average weight of 50 ± 6.5 g in seven treatments (control, 0.5% garlic, 1% garlic, 0.5% Echinacea, 1% Echinacea, 0.5% garlic + 0.5% Echinacea, 1% garlic + 1% Echinacea) and were divided into three replicates. Rainbow trout in all first stages reared for 30 days whit diets containing plant extracts were fed and in the second stage rearing for 15 days only whit control diet (Without extract) were fed, Until time to remove the effect of additives of the fish's body be determined. In order to compare and evaluate the hematological parameters on days zero, 30 and 45 of the breeding period of per replicate three fishes were randomly selected. From fish's caudal vein using the anticoagulant was bloodletting, then, in order to compare and evaluate the hematological parameters, blood samples were tested by standard methods of Hematology. To determine the effect of plant extracts in the bacterial challenge with pathogen, the bacterium yersinia ruckeri was injected intraperitoneally on 30th day and mortality daily was recorded in two weeks. In the first stage of culture, most of the white blood cells (which was significantly different from control treatments) and most of the lymphocytes, hemoglobin and hematocrit (without significant difference from the control treatments) was observed in garlic extract 1% and echinacea extract 0.5% treatments. In the second phase of culture none of hematologic parameters in the experimental treatments there were no significant difference with control treatments (P > 0.05), but most of the lymphocytes was observed in garlic extract 1% treatments. In experiments bacterial challenge with the bacterium Yersinia ruckeri, Mortality in the treatment garlic extract 1% one day later than other treatments began and the lowest mortality accounted. From the results of this study can be conclude that the use of garlic extract 1 %and echinacea extract 0.5% makes stimulates the immune system and increase resistance in rainbow trout.