A serum pregnancy test with a specific radioimmunoassay for moose and elk pregnancy-specific protein B

A double-antibody radioimmunoassay (RIA) specific for elk (Cervus elaphus) and moose (Alces alces) pregnancy-specific protein B (PSPB) was established. Sheep anti-moose PSPB was used for the first antibody and purified placental moose PSPB (mPSPB) was used as a standard. This assay was shown to quantify moose and elk PSPB in serum. When used to detect pregnancy in elk near 40 days after artificial insemination, there was agreement with a bovine RIA at 96%. Accuracy of both RIA's was 93% compared to calving observation. The PSPB concentration in serum of moose increased steadily from 40 to 100-150 days during gestation, but remained steady or decreased slightly between 150 and 190 days. The concentration of PSPB in serum of moose bearing twin fetuses was significantly different and higher than it was in moose bearing a single fetus. A cut-off point of 365 ng/mL PSPB in serum was chosen to separate moose bearing single or twin fetuses at approxmately 10 weeks before parturition. The accuracy of detection of singles and twins was 90.5%. Based on this RIA, pregnancy can be detected in elk and moose and prediction of single or twin pregnancies in moose is possible.