Early pregnancy diagnossis early pregnancy factor (EPF) in the cows

26 SUMMARY Early Pregnancy Diagnosis by Early Pregnancy Factor (EPF) in the Cows The aim of this study was to investigate a possible relationship between the serum activity of early pregnancy factor (EPF) on the days 7 and 21 and the blood serum levels of progesterone on the day 21 following insemination and day 45 rectal examination findings in cows. Possible use of EPF parameter in early diagnosis of pregnancy was also sought. Sixty Brown Swiss cows were used in this study. Blood samples were collected on the days 7 and 21 for EPF activity and on the day 21 for progesterone analysis. Serum EPF and progesterone levels were determined by Rosette Inhibition Test (RIT) and radioimmunassay, respectively. In the RIT analysis, findings above 4 were accepted as pregnant and those equal or below 4 as non-pregnant. The cows with serum progesterone levels above 2.30 ng/ml were evaluated as pregnant. RIT and serum progesterone levels were compared with the rectal examination findings on the day 45 following insemination. Based on the rectal examination findings, accuracy of day 7 and 21 EPF and day 21 progesterone results were as follows: 54.7%, 70.7% and 67.4%, respectively, in the pregnant cows. All three parameters proved to be 100% accurate in the non pregnant animals. Early embryonic deaths significantly affected the diagnosis of early pregnancy results based on the serum EPF and progesterone parameters. Although fertilisation rate was 88.3% of the cows embryonic deaths occurred in 45.3% of the fertilized cows. In conclusion, these findings suggest that determination of EPF activity may be used for diagnosis of early pregnancy and for monitoring continuation of pregnancy. RIT and progesterone analysis methods may be more reliably used for determination of the non-pregnant cows than the pregnant ones.