Análise leucométrica em bovinos tuberculinizados e sua aplicação no monitoramento da leucose enzoótica em rebanhos do Estado de Pernambuco

Abstract

Enzootic Leukosis (EBL) and Bovine Tuberculosis (BT) compromise the immune status of the herds, especially the immunosuppressive potential of bovine leukosis virus (BLV). Several factors interfere with leukocyte values of cattle, but little is known about the effects of BT on them. The aim with the study was to evaluate the leukogram of tuberculinized cattle, with a view to the use of leukocytes as an epidemiologic tool in combating EBL in dairy herds of Pernambuco. 1.000 serum samples from 33 herds of cattle coming from various municipalities in the state were submitted to the serodiagnosis of EBL (AGID), being 920 cattle previously tuberculinized by the simultaneously comparative technique (SCT). Blood smears were prepared of all tuberculinized cattle, and the total and differential leukocyte count was performed using conventional techniques. The evaluation of the influence of BT in leukocyte counts was performed by comparing the results of four experimental groups, according to the results of the AGID and SCT (gTB group - 41 to the positive SCT; group gLEB - the 151 AGID positive, group gNEG - 379 to the negative TSC and AGID, group gINT - 43 positive to both tests). The prevalence rates of TB and LEB were, respectively, 11% (99/920) and 28% (282/1000), with 88% (29/33) of herds contributing at least one animal positive for one or both tests. From the 920 cattle examined, 43 (4,7%) were positive to both tests simultaneously. The mean values of leukocytes and lymphocytes (x 103/mm3 of blood) of the experimental groups were, respectively: gTB 9,6 ± 2,5 and 5,9 ± 1,9; gLEB 13,3 ± 6,3 and 9,1 ± 6,0; gNEG 11,5 ± 3,8 and 7,6 ± 5,1; and gINT 11,8 ± 4,3 and 8,0 ± 3,5. There were significant differences (p<0,05) between leukocytes and lymphocytes, when confronted gTB group (lower values) and gLEB (higher values) with the gNEG group, while gINT group did not differ (p>0,05) in none of the parameters analyzed in relation to the group gNEG. It is concluded that the leukogram is influenced by bovine BT, and health programs to combat LEB in dairy herds in the state of Pernambuco, and include the white blood cell count as an epidemiologic tool wish to consider the strategic prior tuberculin test the herds involved, being discarded cattle that are experiencing imunoalergic test positivity.