Pregnancy diagnosis in sows: enzyme immuno assay measurement of oestrone sulphate in plasma on day 25–30 after insemination in comparison to ultrasound scanning on day 28

Abstract

The overall accuracy of plasma oestrone sulphate (E 1S) and ultrasound pregnancy diagnosis in a group of 953 inseminated sows was 99.0% and 91.2%, respectively. The accuracy of pregnancy diagnosis based on E 1S (day 25–30) for pregnant sows (test sensitivity) as well as that for non-pregnant sows (test specificity) was high (99.4% and 96.9%, respectively). For A-mode ultrasound pregnancy diagnosis (day 28) the test sensitivity was also high (96.2%), but the test specificity was low (55.0%). Litter size at farrowing (total born) was significantly correlated with the E 1S concentration on days 25–28, but the correlation coefficients were rather low (0.20–0.42). It is concluded that pregnancy diagnosis based on E 1S measurement between days 25 and 30 is highly sensitive and specific, but the E 1S concentration can not be used to predict litter size accurately. Especially the high test specificity, together with the ease and rapidity of performance of the EIA procedure, adds considerable to the potential value of E 1S measurement for routine pregnancy diagnosis in pigs.