[Blood bactericidal activity in calves].

Methodical aspects relating to determination of serum-bactericidal capacities were studied, with the view to using them to test the bearing of abiotic environmental factors on defence mechanisms against infections. Communicated are methodical experience by which to enhance the methods used to higher accuracy as well as experience regarding biological variance in calf and results obtained from follow-up checks in which antigens were systematically used. Reference is made also to other methodical issues. The method actually used to determine serum-bactericidal capacity was found to be suitable for an assessment of reactivity of infection defence in calf for its good accuracy. Follow-up checks, using antigens, will enable better assessment of the action of abiotic environmental factors on the complex defence system of calf.