INVESTIGATION ON THE QUANTITATIVE TRANSFE R OF IMMUNOGLOBULINS FROM THE INTESTINES INTO THE BLOOD-SERUM OF NEWBORN LAMBS

A trial with 69 lambs examined the effect of the feeding regime on the transfer of colostral immunoglobulins from the intestinal lumen to th e circulating blood. The lambs received 125 ml of bovine colostral mil k per kg birth weight at each feeding in the first 24 hours after birt h. There were four experimental groups. Feeding intervals were either 2 or 6 hours and the milk was administered with or without doubling th e fluid volume by addition of tap water. Serum concentrations of IgG(1 ), IgG(2), IgM and IgA were measured during the experimental period an d the transport efficiency index for each isotype was calculated. The transport efficiency index represents the relationship between the amo unt of immunoglobulin administered in colostral milk and the concentra tion measured in the blood. Feeding in 2 hour intervals produced maxim um immunoglobulin concentrations at 30 hours, while 6 hour feeding int ervals achieved the same maximal levels at 24 hours. The relative prop ortions of the four immunoglobulin isotypes measured in the blood were unaffected by the feeding interval. Doubling the fluid volume adminis tered while holding the absolute amount of colostral milk constant, re sulted in a disproportionate increase in blood IgG(1) concentration as compared to the other isotypes. Concentrations for IgG(2), IgM and Ig A remained essentially the same as those achieved with undiluted colos tral milk. The feeding regimes tested did not affect endogenous immuno globulin synthesis, growth rate or the health of the lambs.