In order to evaluate the influence of the age on the white blood cell counts of Nelore (Zebu) cattle, 158 blood samples from seven groups of different ages (group I-up to three months; group II-three to six months; group III-six to 12 months; group IV-12 to 24 months; group V-24 to 48 months; group VI-48 to 72 months and group VII-older than 72 months) were studied. The highest and lowest mean values observed were total white blood cell/mm³-16992±4104 (group III) and 10353±2397 (group VI); neutrophils/mm³-3931±1578 (group I) and 2416 ±1118 (group III); eosinophils/ mm³-999±499 (group V) and 265±276 (group II); basophils/mm³-67±88 (group VII) and 39±78 (group III); typical lymphocytes/ mm³-12758±3608 (group III) and 5906±1883 (group VI); atypical lymphocytes/ mm³-1310±603 (group II) and 760±419 (group VI) ; lymphocytes total/ mm³-14079±4027 (group III) and 6666±2059 (group VI); monocytes/mm³-27±62 (group I) and 0 (group III). The differences (p>0.05) observed among the groups in relation to total white blood cell, lymphocytes, neutrophils and eosinophils can be related to the influence of the age on leukogram of Nelore (Zebu) cattle raised in São Paulo- Brazil.
hematology; leukogram; age; cattle; Nelore breed
