[Age-related dynamics of adenovirus antibodies in calves].

Experiments were carried out on calves from 3 cattle-breeding farms, failing to fight respiratory disorders, aged 10-120 days, in order to prove the participation of cattle adenoviruses in the etiology of the illness. Age susceptibility, as well as the dynamics of passive and active antibodies in young calves against adenoviruses were studied with regard to technology of their breeding. It was proved that the persistence of antiadenoviral antibodies of colostral origin was determined within the limits of 4-8 weeks, whereas the infection of the young and growing calves with adenoviruses took place most frequently within the limits of 2-16 weeks after their birth and this process is greatly influenced by the regime of breeding. An earlier grouping of calves (8-10 days after their birth) advances age susceptibility, and conversely. The regrouping of calves from unsuccessful farms at the age of 20 days led to a later manifestation of adenoviral disease in the group. In the blood serum of calves from one farm were proved virus neutralizing antibodies, corresponding simultaneously to cattle adenoviruses serotypes 3 and 8, as well as precipitating ones against group specific antigens from I and II adenoviral subgroups. It was proved that 40-50% of the growing calves suffer from adenoviral infection.