Detection of pregnancy-associated glycoproteins in milk and blood as a test for early pregnancy in dairy cows.

The objective of our study was to evaluate 2 pregnancy-associated glycoprotein (PAG)-based enzyme-linked immunosorbent assays (ELISAs) for use with either blood or milk. From 12 dairy farms, 116 Montbéliarde or Holstein cows were selected that had either undergone artificial insemination (AI; n = 102) or had calved (n = 14) 2-3 months earlier and had not undergone any further AI. Serum, plasma, and milk were obtained from all cows; serum and plasma were analyzed using the blood pregnancy test and milk using the milk pregnancy test.