[Bovine leukemia virus antibody levels in the blood and mammary gland secretion in cows in the perinatal period].

The titer of BLV-antibodies was estimated in the mammary gland secretion of 18 cows, naturally infected with BLV. Mammary gland secretion samples were collected every week since the 8th week ante partum and every day during the first week post partum. At the same time, blood samples were collected. The examination showed a marked decrease of antibody titer in the blood serum since the 5th week ante partum to the 2nd day post partum. Negative serological results were noticed temporary in the blood serum. The results indicate that serological examination of mammary gland secretion (dry secretion, colostrum) may be helpful because of high concentration of antibodies in the these secretions.