Production and Characterization of Polyclonal Antibodies for Diagnosis of Pregnancy in Cattle

Pregnancy-specific protein B (PSPB) is produced by binucleate trophoblast cells in the bovine placenta around the time of implantation. We produced anti-PSPB polyclonal antibodies to detect PSPB in the serum of Peranakan Ongole (PO) pregnant cows. Six New Zealand White (NZW) Rabbits were immunized with 40-60 kDa protein in combination with adjuvants for antibody production. Sera of experimental animals (n = 30) were taken from the auricular vein and subjected to the ELISA test. The highest antibody titer was used to test the specificity of antibodies using the dot blot method. Antibody titer was observed during the first week, while the highest antibody titer (OD = 0.3755) was found during the 3rd week of bleeding, which decreased gradually during the subsequent weeks. The sensitivity test showed an ability of anti-PSPB to detect PSPB in the serum of pregnant cows from 90 days of gestation and as low as 1:120. The study concludes the potential utility of anti-PSPB polyclonal antibodies for the detection of pregnancy in cows.