Comparison of plasma progesterone, transrectal ultrasound and pregnancy specific proteins (PSPB) used for pregnancy diagnosis in reindeer

The study aimed to compare plasma progesterone concentrations, rectal ultra sonography and plasma concentrations of pregnancy-specific protein B (PSPB) used for pregnancy diagnosis in reindeer. A total of 1595 blood plasma sam ples were collected between 1991 and 1996 from 3 semidomestic reindeer (Ran gifer tarandus tarandus) herds on the Norwegian mainland (Mageroy, Soroy, F ilefjell) and from 92 wild Svalbard reindeer (Rangifer tarandus platyrhynch us). Samples were collected between January and late April. plasma levels o f progesterone and PSPB were measured and used as indicators of pregnancy. In addition, animals from the Filefjell herd and the Svalbard reindeer were investigated using transrectal ultrasound. The results showed that plasma progesterone lower than 7 nmol 1(-1) rarely occurs in females diagnosed pre gnant either by ultrasound or by observing a calf at foot 7 months after bl ood sampling. A very good agreement was found between plasma progesterone a nd PSPB when used for pregnancy diagnosis. On the Norwegian mainland, but n ot to the same extent on Svalbard, a high proportion of females with a high progesterone concentration was diagnosed not pregnant by ultrasound. This probably reflects a high rate of false negative diagnoses by the ultrasound method rather than false positives in the progesterone analysis.