Porcine Corticosteroid-Binding Globulin: Binding Properties and Levels in Stress-Susceptible Swine

Corticosteroid binding activity was estimated by a modified protein binding technique in plasma samples from three swine herds. Swine from a herd bred to be stress-susceptible had significantly higher mean plasma cortisol and corticosteroid-binding globulin (CBG) levels with a significantly lower mean cortisol-CBG association constant than normal swine. The data suggest that boars have higher CBG levels than barrows and gilts. No significant relationships could be established between CBG activity and carcass traits of gilts or boars. Information suggesting thyroid hyperactivity in stress-susceptible swine is presented.