Effects of pasteurization of colostrum on subsequent serum lactoferrin concentration and neutrophil superoxide production in calves

Objective-To determine the effects of pasteurization of colostrum on serum lactoferrin concentration and neutrophil oxidative function by comparing va lues from calves given pasteurized (76 C, 15 minutes) colostrum versus calv es given fresh frozen colostrum. Animals-8 Holstein bull calves were used to study the effects of pasteuriza tion of colostrum on the absorption of lactoferrin and neutrophil oxidative burst. Three additional calves were used to study the effect of exogenous lactoferrin on neutrophil oxidative burst. Methods-Calves were fed fresh frozen or heat pasteurized colostrum (76 C fo r 15 minutes) via esophageal feeder within 4 hours of birth. Neutrophils we re isolated from whole blood samples. Neutrophil oxidative burst was induce d by phorbol ester (300 ng/ml) stimulation of cells (1 X 10(6) cells) at 37 C, Serum lactoferrin concentrations were compared, using immunoblot analys is. Serum IgG concentrations were determined by radial immunoassay. Compari sons were made between the use of the 2 types of colostrum in calves by mea suring subsequent serum IgG and lactoferrin concentrations and neutrophil s uperoxide production. Results-Serum IgG and lactoferrin concentrations increased more in calves r eceiving fresh frozen colostrum. Neutrophil superoxide production was highe r in neutrophils prepared from calves receiving fresh frozen colostrum. Col ostral lactoferrin addition to neutrophil incubations resulted in increased oxidative burst. Conclusions and Clinical Relevance-Compared with calves given fresh frozen colostrum, calves given pasteurized colostrum had decreased serum IgG and l actoferrin concentrations and neutrophil superoxide production 24 hours aft er administration. These results suggest that pasteurizing bovine colostrum at 76 C for 15 minutes has substantial effects on passive transfer of prot eins and neutrophil function.