PSI-30 Evaluation of urine estrone sulfate (P-Test) in beef cattle as an alternative pregnancy detection method

Abstract Pregnancy detection in cattle can be expensive and labor intensive to producers. A simple, cost-efficient method of determining early pregnancy, chute side, is lacking within the industry. This study tested various proven pregnancy detection methods against an alternative method. Pregnancy was assessed by ultrasonography, blood serum pregnancy-specific protein B (PSPB), and urine estrone sulfate (“P-Test”). A fixed timed AI (FTAI) protocol was conducted on 14 predominantly British cattle housed at Tarleton State University in Stephenville, TX. Cows were synchronized using the co-synch plus 7 day CIDR protocol, with PGF injection of d 7. Heifers were synchronized similarly with the exception of GnRH injection on d 1. Estrotech patch scores (1 – 4, 1 showing little signs of estrus to 4 presenting signs of estrus) were utilized to indicate estrus activity prior to FTAI (21.4% vs. 78.6% females scored 1 vs. 4, respectively). FTAI was performed on protocol d 10 along with a 2mL injection of GnRH. Serum for PSPB analysis was collected at d 30 and 60 post insemination, while urine was sampled on d 60. Overall 53.8% (ultrasonography) and 71.4% (PSPB) of cattle were determined to be pregnant at d 30 post FTAI. Chi squared analysis proved that PSPB and ultrasound were similar at detecting pregnancy (P = 0.04). At d 60 “P-Test” color varied indicating differing levels of estrone sulfate. A t-test revealed increased PSPB from d 30–60 post FTAI (P < 0.0001); however, “P-Test” could not predict similar results (P = 0.655). Data suggest the “P-Test” is not a consistent method to diagnose early pregnancy. Future studies may be warranted to investigate a more desirable time point for utilizing the chute side “P-Test” as a reliable method to determine pregnancy.