Absorption and endogenous production of immunoglobulins in calves

Abstract

There is little or no placental transfer of antibody in ruminants, the young acquiring passive immunity soon after birth by the intestinal absorption of antibody present in the dam’s colostrum. Thus, there is an abrupt change in the concentration of antibody or total immunoglobulin in blood serum of newborn ruminants from negligible values at birth to high values soon after ingesting colostrum (cf. Brambell, 1970). Subsequently, the concentration of immunoglobulin in serum declines, due primarily to biological decay of the passively acquired protein, but after some weeks the young, responding to the many antigenic influences to which it is now exposed, begins to synthesize increasing quantities of immunoglobulin. Hence, there must be a period just prior to the onset of endogenous synthesis when immunoglobulin concentration in blood would be at a minimum. It is possible that the concentration of one or more of the classes of immunoglobulins reach such low levels at this time that young ruminants are more susceptible to infectious diseases.