THE ACCURACY OF ENZYME-LINKED-IMMUNOSORBENT-ASSAY AND LATEX AGGLUTINATION PROGESTERONE TEST FOR THE VALIDATION OF ESTRUS AND EARLY-PREGNANCY DIAGNOSIS IN DAIRY-CATTLE

The accuracy of the enzyme-linked immunosorbent assay (ELISA) and the latex agglutination (LA) on-farm progesterone kit for detecting estrus and diagnosing early pregnancy was investigated in this study. Italia n Friesian dairy cows (n=82) from 6 dairy herds were used for the coll ection of foremilk samples at the time of breeding and at 19, 21, and 23 days post insemination. Pregnancy status was ascertained by uterine palpation per rectum 40 to 60 days post insemination. Progesterone le vels were affected by herd, percentage of milk fat, and the day of tes ting x diagnosis interaction. Validation of estrus by qualitative on-f arm tests was 74.6% (LA) and 100.0% (ELISA) accurate using 0.5 ng/ml o f progesterone as the RIA estimate for estrus. The accuracy rate for e arly pregnancy diagnosis by RIA was 68.4 to 83.8% for day 19 and day 2 1, respectively, while the detection rate for nonpregnancy was 84.6 to 100% on day 19 and day 21, respectively, as compared with uterine pal pation per rectum. The average accuracy rate for early pregnancy diagn osis ranged from 84.7 to 92.3% for the LA and ELISA tests, respectivel y; the nonpregnancy rate was correctly predicted 93.9 to 68.2% for the LA and ELISA tests, respectively.