title: [The immune status of cattle at critical age periods].
abstract: The investigations were held on the calves of the red steppe breed and its cross-breeds with Holsteins [correction of Golshtins] in critical age periods (2, 6, 17 months and in heifers). It is established, that the immune protection of the cattle organism at the early stages of ontogenesis (2 months) is provided on the whole at the expense of the phagocytosing activity of the blood neutrophils. T- and B-systems of the immunity are formed with age. At the age of 2 and 6 months the cross-bred calves yield to pure-bred calves in majority of the indices of the immune status, though the trustworthy difference is marked only in the indices of T-helpers and CIC. By 17 month the cross-bred heifers of the first generation trustworthy excel the red steppe heifers in the quantity of T-active lymphocytes and yield to the latter in the contents of CIC in the blood. The cross-bred heifers of the second generation excel the heifers of the same age in many indices of the immune status but the difference is not trustworthy. The heifers of the all three groups have no trustworthy differences.
authors.forename: I I
authors.initials: II
authors.lastname: Haranovych
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002417:Cattle / Q000276:immunology*; D003433:Crosses, Genetic; D005260:Female; D007111:Immunity, Cellular; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology