Early pregnancy diagnosis by measurement of pregnancyassociated glycoproteins (PAGs) in blood serum and milk of dairy cows

Nasko Vasilev, Ivan Fasulkov, Manol Karadaev, Boiana Ivanova

Abstract: The present study aimed to determine the efficiency of two commercial ELISA tests for measuring pregnancy-associated glycoproteins (PAGs) in blood serum and milk in relation to early pregnancy diagnosis in lactating Holstein-Friesian cows. A total of 144 blood and milk samples form lactating cows were collected 30 days after artificial insemination and subjected to PAGs assay. Pregnancyspecific glycoproteins were determined by ELISA method using of Ruminant Pregnancy PAG test for milk and blood. A transrectal ultrasonography for pregnancy detection was performed 45 days after insemination. The obtained data of PAGs and ultrasound diagnoses were compared. The results for PAGs concentrations in serum and milk and indicators for efficiency of both tests were processed by computer statistical program (Statistica 7, Microsoft Corp. 1984-2000 Inc.) and compared using nonparametric method of comparison of means and percentages. In conclusion, the PAGs concentrations in blood serum were significantly (P < 0.05) higher than those in milk. Sensitivity, specificity and
accuracy of both tests were close with a tendency to better result after measuring PAGs in blood serum. The evaluated tests have high efficiency and can be used as an alternative of other methods for early pregnancy diagnosis in dairy cows.

Keywords: ELISA; lactating cows; Pregnancy-associated glycoproteins; serum and milk

Date published: 2023-02-27