[Trial of a hyperimmune serum against para-influenza 3, bovine adenovirus 1, infectious rhinotracheitis and mucosal disease].

A four-valent serum was obtained by parallel hyperimmunization of cattle with live viral suspensions of parainfluenza-3, bovine adenovirus I, the virus of infectious rhinotracheitis and the mucous disease virus. The serum's neutralizing titres are between 1:1280 and 1:2560. The lasting exploitation of serum producing cattle indicates that no competition exists between the four antigens used in the process of hyperimmunization. Experimental testing of the serum on calves and its application in practical work proved its prophylactic and medicative effect. These results confirm the thesis that the use of passive immunoprophylaxis is needed in respiratory diseases of calves under conditions existing in intensive cattle-breeding.