INVESTIGATIONS OF EMBRYO-DERIVED PLATELET ACTIVATION FACTOR AND EARLY-PREGNANCY FACTOR IN BOVINE AFTER EMBRYO TRANSFER

At the earliest developmental stage embryos derived platelet activating factor (EDPAF) and the early pregnancy factor (EPF) can be used to detect pregnancy. Bovine embryos producing higher levels of EDPAF within 24 hours of culture (P < 0,02) were transferred successfully. Transfer of embryos that did not secret EDPAF never resulted in a pregnancy. PAF of maternal or embryonic origin was detected in the serum of pregnant recipients (n = 5) by means of an indirect bioassay at day 1 (P < 0,05) day 5 (P < 0,05) and day 12 (P < 0,05). In three recipients which did not become pregnant PAF was not activated in serum. Within the same animals EPF activity was determined by means of an indirect ELISA. Significant differences were found between pregnant and nonpregnant recipients at day 1 and 9 after transfer.