Accuracy of pregnancy specific protein-b (PSPB) test for early pregnancy diagnosis in Kedah-Kelantan cattle

Early pregnancy diagnosis is crucial in cattle production since it aids in the management and reduces the risk of embryonic loss. The study aims to determine the concentration of PSPB in serum and urine associated with the phenotypic variables. Next, determine the accuracy of the PSPB concentration in both biomarkers. Ten cattle (n=10) were chosen to collect the blood serum (2 ml) and urine samples on specific Days 0, 24, 42, and 164 after the artificial insemination (AI). Rectal palpation was performed to confirm the pregnancy status on Day 240. All collected samples were centrifuged at 3000 rpm for 15 minutes at 4°C. The serum and urine samples were evaluated using a competitive ELISA test kit and read at 450 nm wavelength speed. Using the kit's standard optical density (OD) value, an equation was developed to calculate the concentration of PSPB in serum and urine. RISDA farm records gave phenotypic factor information and separated cattle into range groups based on age (G1= 4 years old, G2= 5 years old, G3= >6 years old), parity (P1= 1st, P2= 2nd, P3= 3rd), and live weight (L1= 239 kg, L2= 240-280 kg, L3> 280 kg). The PSPB concentration in serum and urine was determined using One-Way ANOVA (P<0.05) and the Turkey test in SPSS version 26. Next, the variables parity and live weight were chosen for analysis using Pearson's correlation coefficient and multilinear regression with a P-value less than 0.01 considered significant. According to the findings, PSPB concentration in serum steadily rose from Day 0(2.63 ng/ml) to Day 164 (15.98 ng/ml), but PSPB concentration in urine exhibited a high peak concentration of ELISA test sensitivity (24 ng/ml) at Day 0 (21.79 ng/ml). PSPB concentration in G1 serum steadily increased from Day 0(0.49 ng/ml) to Day 164 (16.85 ng/ml); however, PSPB concentration in urine began at a high peak concentration from Day 0 to Day 164. For parity, the serum PSPB levels in P2 were steadily raised from Day 0 (4.15 ng/ml) to Day 164 (17.22 ng/ml). However, the PSPB concentration in urine in P2 increased around the highest peak from Day 0 (18.83 ng/ml) to Day 164 (23.28 ng/ml). PSPB serum concentrations in L2 were steadily raised from Day 0 (2.91 ng/ml) to Day 164 (18.70 ng/ml). Meanwhile, the PSPB concentration in urine in L2 remained at its maximum level (24.55 ng/ml) from Day 0 to Day 164. The phenotypic factors variable was not significant (P>0.05). The sensitivity and specificity of serum (Sen serum= 66.7%, Spe serum= 75%) and urine (Sen urine =100%, Spe urine= 0%) biomarkers revealed that serum biomarkers were more accurate (70%) than urine biomarkers (60%). The R2 values of serum and urine biomarkers from the multilinear regression test were 35% and 36.1%, respectively. In conclusion, the presence of PSPB in both samples can be detected as early as 15 days post Al. In addition, the model developed can determine the PSPB concentration of both biomarkers based on parity and live weight status, and it has the potential to make simple pregnancy test kits.