Pregnancy determination by use of pregnancy-specific protein B radioimmunoassay in llamas

Blood samples were obtained from each of 30 llamas: 22 females that had been exposed to a male and were assumed to be pregnant (gestational stage, 2 to 244 days), 1 female that had not been exposed to a male, 3 sexually intact males, 1 castrated male, and 3 females with congenital reproductive anomalies. Serum was tested for the presence of pregnancy-specific protein B, using a radioimmunoassay that accurately detected pregnancy in cattle, sheep, and other ruminants. Pregnancy-specific protein B was not detected in the serum of the 30 llamas. On the basis of our results, the radioimmunoassay for pregnancy-specific protein B cannot be used in llamas for detection of pregnancy.