The Development of Hematological Profile in Experimental Groups of Broiler Chickens Given Overdoses of Erythromycin

Normal 0 false false false MicrosoftInternetExplorer4 Introduction : The use of antibiotics in broiler rearing was and is still a widespread practice. Concerns about the risk of antibioresistance installation and safety of the products obtained from birds exposed to antibiotics make this issue one of extreme importance. Aims : The purpose of this research was to investigate the development of erythrocyte and leukocyte counts in broilers subjected to experimental overdose of an erythromycin based product. Materials and methods : Two experimental groups of broilers (n = 12) were subjected to treatment with erythromycin based product (5X respectively 10X therapeutic dose) over a 5 day period and a control group (n = 12) was kept in identical conditions of housing and feeding. Blood samples were collected from the investigated birds post-treatment, respectively at end of the experimental period. Investigations focused on the main hematological parameters: erythrocytes and leucocytes counts, hemoglobin, hematocrit, mean erythrocyte constants (MCV, MCH, MCHC) and the proportion of leukocyte subpopulations. Individual and mean values were statistically analyzed using ANOVA applications. Results: The recorded values for the investigated hematological parameters showed minor fluctuations in mean and individual data. Statistical analysis revealed no significant changes in the investigated parameters except for hemoglobin concentration (p=0.0002), MCHC (p= 0.0004) and monocyte subpopulation where the recorded differences were considered very significant (p = 0.0021). Conclusions: The data from the experiment show that the overdose of the erythromycin based product did not cause major changes in the investigated parameters. Statistically significant alterations were only observed in the monocyte subpopulation of the group exposed to 5X therapeutic dose not the one exposed to the maximum dose (as it would be expected). In the context this experiment the monocytosis post-treatment can be attributed to prolonged persistence of these cells in the bloodstream associated with a possible stimulation of the nonspecific defense systems in the birds treated with the intermediary dose.