Pregnancy status determination in mares using a rapid lateral flow test for measuring serum oestrone sulphate.

The study focuses on creating a quick and efficient way to determine pregnancy in horses by measuring serum oestrone sulphate levels with a rapid lateral flow immunoassay. The results demonstrate that the method effectively identifies pregnant and non-pregnant mares, providing a practical alternative to traditional laboratory-based tests.

Objective of the Research

• The research aims to devise a quick and reliable method for determining the pregnancy status in mares. This method is based on measuring the serum oestrone sulphate (OS) concentrations using a rapid lateral flow immunoassay. The effectiveness of the assay was determined visually.

Methodology

• The researchers used serum samples, specifically from mares that were more than 100 days post-mating. The sample size was substantial with 701 samples being tested.
• The team used a nitrocellulose membrane-based lateral flow immunoassay device for performing the assay.
• They put into use the OS enzyme immunoassay (EIA) and the recorded instances of the mares returning to oestrus or foaling for comparing and validating the results.
• The lateral flow test was developed using a specific membrane-bound antigen and an OS-detection monoclonal antibody that was linked with colloidal gold for visible detection.

Results Observed

• It was observed that serum samples having OS concentrations less than 10 ng/ml, which indicates non-pregnancy in mares post 100 days of mating, generated a highly visible test dot and control line.
• On the other hand, serum samples with OS concentrations greater than 50 ng/ml, indicating pregnancy, resulted in the generation of a control line only.
• The test successfully identified 98.7% of the non-pregnant mares and 97.1% of the pregnant mares that were post 100 days of mating.
• Moreover, the lateral flow test devices showed stability for at least 12 months when stored at 4 degrees C, sealed in aluminium pouches with desiccant.

Conclusion

• The developed lateral flow immunoassay is a valuable tool for determining pregnancy status in mares. It presents a novel, swift and easy-to-use practical alternative to the traditional immunoassays conducted in laboratories for measuring serum OS concentrations in mares to determine their pregnancy status.