Evaluation Of The Method Of ELISA For Detection Of Bovine Pregnancy-associated Glycoprotein

It was of great significance for improving reproductive efficiency of dairy cows to detect the nonpregnant cows and take a second mating in time via early pregnancy diagnosis in dairy industry.In this study, an early pregnancy detection kit based on ELISA which detected Number of the bovine pregnancy-associated glycoprotein(PAG ELISA) was designed for early pregnancy diagnosis, and the accuracy, nonpregnant days, calving interval and breeding interval were evaluated. The main results were as follows:1. To determine the accuracy of pregnancy-associated glycoprotein(PAG) ELISA test in identifying pregnancy status 28 d after insemination, 273 Holstein cows were selected in this study.The sensitivity, specificity, predictive positive value, predictive negative value and accuracy of the PAG ELISA kit were 100%, 75.5%, 86.5%, 100% and 0.5% respectively. Which was equal to the results of rectum pregnancy test after 75 days and could be used for early pregnancy diagnosis in dairy cows.2.The average nonpregnant days were 156.73±86.34 d(n=252)before using the PAG ELISA kit while 134.06±72.65 d(n=308)after, which suggested that by using the PAG ELISA kit could decrease the nonpregnant days significantly(P<0.01).3.The calving interval were 444.35±89.24 d(n=189) before using the PAG ELISA kit while 407.53±70.40 d(n=237) after, which suggested that by using the PAG ELISA kit could decrease the dairy cows calving interval significantly(P<0.01).4. The breeding interval were 38.80±2.45 d(n=863) before using the PAG ELISA kit while 33.22±1.06 d(n=989) after, which suggested that by using the PAG ELISA kit could decrease the breeding interval significantly(P<0.01).The PAG ELISA kit, which could decrease the dairy cows nonpregnant days, calving interval and breeding interval significantly, was a fast, easy and reliable method for early pregnancy diagnosis in farm.