DETECTION OF INTERLEUKIN-1-BETA IN SERA AND COLOSTRUM OF DAIRY-CATTLEAND IN SERA OF NEONATES

In order to obtain basic information about bovine interleukin-1 IL-1 b eta, levels of IL-1 beta in sera and milk of clinically normal mature Holstein cattle before and after parturition and in sera of newborn ca lves were examined by ELISA. The level of IL-1 beta was undetectable i n sera of mature cattle around the time of artificial insemination, bu t the concentration gradually increased and reached a peak at parturit ion and then decreased again to an undetectable level. IL-1 beta in mi lk was detected on the day of parturition but not thereafter. IL-1 bet a mRNA was detected by reverse transcription-polymerase chain reaction in the cells from milk collected during 20 days before and 2 to 3 day s after parturition, but was not detected thereafter. Although IL-1 be ta was not detected in all the sera of newborn calves, the concentrati on transiently increased with peak titers on day 3 and became undetect able by day 14 after birth. Newborns that showed serum IL-1 beta on da y 3 had been fed on colostrum in which the IL-1 beta concentration was significantly higher than that in colostrum that had been fed to newb orns having no detectable IL-1 beta on day 3. These results indicate t hat IL-1 beta is induced in association with pregnancy in healthy dair y cattle and that the cytokine might be transferred to neonates via co lostrum.