[Twenty-four hour changes in the value of the liver clearance of antipyrine in calves during the neonatal period].

Twenty-four-hour changes in the value of the liver clearance coefficient of antipyrine in 10 calves of ncb. race, aged 28-30 days were examined. The findings made it possible to separate 2 subgroups among the examined animals: 6 calves eliminated antipyrine from plasma more quickly during the day than at night and 4 calves - more quickly at night than in the day. To verify the observed differences 3 days after the first examination another antipyrine test was performed on 6 calves (3 from the "night" group and 3 from the "day" group). It has been found that animals which had the tendency to quicker elimination (metabolism) of the antipyrine during the day confirmed it in the second examination. The same regularity has been observed for the calves which quicker eliminate antipyrine from plasma at night.