Wybrane wskazniki nieswoistej i swoistej odpornosci u owiec zakazonych naturalnie wirusem parainfluenzy 3 [Pl-3], adenowirusem 5 [Adeno-5] oraz wirusem syncytialnym [RSV]

The observations were done in two groups of healthy sheep. Group A — 20 animals from 4 large scale farms, with antibodies to PI-3, Adeno-5 and RCV. In these farms symptoms of the respiratory tract infections were noted. Group B-10 animals (control) in one farm free of diseases. The following parameters were examined in blood taken from the external jugular vein at time 1, 30 and 60 days: ability to adsorb and to reduce NBT in a spontaneous and stimulated tests by neutrophils, myeloperoxidase activity of neutrophils (MPO), activity of serum lysozyme (LZ), content of serum IgG, IgM and IgA, titre of specific antibodies against PI-3, Adeno-5 and RSV. It was found that asymptomatic infection caused by PI-3, Adeno-5 and RSV decreased the activity of MPO, level of LZ, IgM and partially IgG and values of a stimulated test of NBT reduction. These changes predipose the activation of latent and asymptomatic viral and bacterial infections, which commonly appear in sheep.