Preferential decay of passively acquired immunoglobulins recognizing shared gram-negative core antigens in neonatal swine.

Serum immunoglobulins of the IgG isotype recognizing common gram-negative cell core epitopes were serially measured by use of a direct ELISA on blood obtained from 10 neonatal swine. An R-mutant Escherichia coli (strain J5) was used as a plate antigen. Total serum IgG was measured by use of radial immunodiffusion. Half-lives of core antigen-specific IgG (6.81 days) and total serum IgG (14.85 days) were dramatically different (P less than 0.01).