摘要:Colostrum samples were collected from 12 Throughbred mares (6-15 years old) at 3 farms located in Hidaka district, Hokkaido, Japan, to clarify the effects of rations and age on calcium, copper and zinc concentrations in mare’s colostrum. Average concentrations of all colostral calcium, copper and zinc were 82.8 mg/dl, 0.82 ppm and 7.76 ppm, respectively. Calcium, copper and zinc contents of rations for mares before parturition varied with the farms. However colostral calcium, copper and zinc concentrations were not different among the farms. There were significant negative correlationships between age of mares and colostral copper or zinc concentrations. It is suggested that copper and zinc intakes of the newborn foals born from older dams may diminish.