Abstract
Hemoplasma infection in peripheral red blood cells was investigated in periparturient cows and their neonatal calves to determine its prevalence in Iwate Prefecture and to examine the possibility of vertical infection. Blood samples were collected from 61 cattle in one dairy farm in Kuzumaki City on July 28, 2010（Experiment 1）. Blood and/or milk samples were collected from postparturient cows and their neonatal calves at 0, 1, 2, and 4 weeks after parturition（Experiment 2）. In Experiment 1, Mycoplasma wenyonii or Candidatus Mycoplasma haemobos infection was detected in 76.9%（10/13）of calves, 100%（15/15）of heifers and 75.8%（25/33）of cows. In Experiment 2, M. wenyonii and C. M. haemobos were detected in 6.7%（1/15）and 60.0%（9/15）at Week 0, 6.7%（1/15）and 73.3%（11/15）at Week 1, and 13.3%（2/15）and 73.3%（11/15）at Week 2, respectively, in the neonatal calves. These results indicate the possibility of vertical infection of C. M. haemobos.
