Characterization of the Serum and Secretory Immune Systems of the Cow and Sheep

Abstract

The secretory immune systems of the cow and sheep were found to be strikingly similar. The principal immunoglobulin in the saliva and colostrum of both species is a “fast” 7 S γ G1 protein which is low in carbohydrate. Although suggestive evidence was obtained for a 10 S secretory immunoglobulin, proof of its existence must await isolation and complete separation from the major 7 S γ G1 component. The secretory 7 S γ G1 is immunologically identical to the γ G1 of serum and in this study no evidence of a component analogous to the human secretory “piece” was detected.