RESUMEN
Some parameters of cell-mediated immunity (phagocytic activity PA and phagocytic index PI, metabolic activity and migration-inhibitive factor MIF of blood leucocytes) were investigated in calves experimentally infected with IBR virus (group II) and in calves premedicated with glucan seven days before infection (group I). A significant increase in the percentage of phagocytizing cells was observed in both groups of animals on days 2-4 of the experiment (P < 0.01) in comparison with the values before infection. If the two groups of animals were confronted with each other, there was a significant difference in the percentage of phagocytizing cells on days 1 and 2 after infection (P < 0.05), with the higher average values in the calves which were only infected. An evaluation of PI showed a statistically significant difference only in the glucan-treated calves on day 7 after its administration (P < 0.05), i.e. on day zero of the experiment. The inhibition of leucocyte migration ability was found on day 1 after infection, and it persisted for four days, without any significant differences between the groups. An evaluation of the metabolic activity of leucocytes (INT-test) showed a decrease in the calves of both groups in comparison with the initial value, without any significant differences when the values were confronted with each other.