Earlier Detection of Ruminant Pregnancy

RIA Method to Detect Pregnancy in Livestock Weeks Ahead of Industry Standard

At a Glance

Researchers at Colorado State University have developed a patented sensitive radioimmunoassay (RIA) for bovine and ovine interferon tau (IFNT) to determine pregnancy 14 days earlier than industry standard.


The current gold standard for determining pregnancy status in cattle is through rectal ultrasound on day 32 of predicted/possible pregnancy. By completing the patented RIA for IFNT on Day 18, accurately determining pregnancy status, it is possible to make re-breeding decisions for non-pregnant cows 14 days earlier – having great economic impact for dairy and beef cattle operations.


  • IFNT is only produced by the trophectoderm cells of the ruminant embryo
  • Lack of detection of IFNT is key in managing ruminant reproductive cycles
Last Updated: November 2019
Calf and Cow

Available for Licensing


Thomas R Hansen
Jared J Romero
Torrance M Nett
Jessica Prenni
Kevin McSweeney
Fuller W Bazer
Alfredo Q Antoniazzi

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Steve Foster