Serum creatine kinase activity as a selection criterion for stress susceptibility after standardised stress in pigs.

Estimation of serum creatine kinase isoenzyme activity was used as a selection criterion for stress sensitivity in pigs 8-12 weeks of age, classified for stress susceptibility as positive to halothane anaesthesia. Standardized stress was provoked by administration of adrenocorticotropic hormone or synstigmine. The experiments were performed under experimental conditions in permanently catheterized animals and in a field trial. It was shown that the stress inductors can be used as a selection criterion for stress sensitivity in catheterized animals by estimation of the CK-MM isoenzyme activity 20-24 h after administration of the inductor. In cases where the individual reaction to halothane anaesthesia is unclear and non classifiable, CK-MM isoenzyme assay performed before and 24 h after the halothane test, may also be useful under practical conditions as an additional indicator of stress sensitivity.