[ abattoir survey on prevalence of enzootic bovine leukosis virus infection and associated clinical, haematological and flow cytometric findings in holestein cattle in Tehran]

ABSTRACT

Bovine leukosis virus [BLV] is a retrovirus that primarily affects lymphoid tissue of cattle. To determine the seroprevalence of Enzootic Bovine Leukosis Virus infection and its effects on some clinical, hematological and flow cytometric indications, this study was conducted on 197 Holstein cattle slaughtered in an abattoir in Tehran province. ELISA gp5 1 test of the obtained serums of the animals showed that the mean of infection rates was 22.3%. Age arrangement of the relative frequencies of the infection showed a significant correlation between EBLV infection and age increasing [0.001infection rates in cattle with any clinical problems or macroscopic pathological lesions and in apparently normal animals [0.001infection and sex and body condition score. With omitting the animals with any clinical problems or macroscopic pathological lesions and stressed ones, because of probability of the secondary changes in hematological indications of them, seropositive cattle had higher total leukocyte counts [0.01T-lymphocyte [CD4+] percentage [0.01cattle. In addition there was a positive correlation between the number of B-lymphocyte [CD21+] and total leukocyte counts and lymphocyte percentage in seropositive cattle. Results of this study depicted high seroprevalence rate of Enzootic Bovine Leukosis Virus infection in the surveyed animals and lower CD4+-cells percentage in seropositive cattle than seronegative ones