ACCURACY OF PREGNANCY-ASSOCIATED GLYCOPROTEIN-ENZYME-LINKED IMMUNOSORBENT ASSAY (PAG-ELISA) IN EARLY PREGNANCY DETECTION IN WATER BUFFALOES

Abstract

The present study compared the accuracy of PAG-ELISA in blood and milk samples from water buffaloes. Fifty-three lactating buffaloes were subjected to fixed-time artificial insemination (FTAI). The PAG level in blood was determined on days 25 and 30, while in milk it was determined on days 26 and 30 post-FTAI. Transrectal ultrasonography (TRUS), the gold standard for pregnancy diagnosis, was done on day 40 post-FTAI. Out of 53 cows inseminated, 30 were confirmed pregnant by TRUS. In these pregnant animals, 93% and 100% sensitivity were achieved in blood at days 25 and 30, respectively, while 40% and 93% were achieved in milk at days 26 and 30, respectively. In terms of specificity, 100% of the assay was achieved in both blood and milk samples on all days of collection. On day 30, 100% overall accuracy for blood was achieved, while it was only 96% for milk. Blood PAG-ELISA is more accurate and can detect pregnancy earlier than its milk counterpart. Milk PAG-ELISA, however, can serve as an alternative for being a non-invasive and stress-free method. In conclusion, PAG-ELISA provides a highly efficient and reliable means to detect early pregnancy and facilitate rebreeding program in water buffaloes.