Erythrocyte diameter of zebu Nelore cattle: influence of age factors, sex factors and Nelore breed lines

Abstract

The erythrocyte diameter of zebu Nelore cattle raised in the State of São Paulo were determined with aim of the analyzing the influence of age factors, sex factors and breed lines factors. In order to get up the subject, blood samples from 170 healthy animals free of blood parasites were collected and submitted to standard hematological techniques and mensuration of the erythrocyte diameter by blood smears glass with Rosenfeld color. To evaluate the influence of age, 140 Nelore Standard were divided into seven age groups, from birth to over 72 month, including 20 animals for each groups. The influence of sex factors, were evaluated using 80 adult animals: 40 male and 40 female. The influence of the breed lines factors, were evaluated using 60 zebus, 15 animals of different varieties or strain, the Nelore: Standard, Lemgruber, “Mocho” and Kuleia. The results demonstrated significant differences (p< 0,05) into the age group: the erythrocyte diameter increase, from the group of calves neonates up to three months (4,72 ± 0,29µm) to the group formed by adult animal above of 72 months (5,45 ± 0,17µm). No had influence of the sex and breed lines factors in this study. The average standard values of the erythrocyte diameter of the Nelore cattle were 5,24 ± 0,62µm and the range from 3,5 to 7,5µm. The results demonstrated the influence of age on the erythrocyte diameter of zebu Nelore cattle.