Determine when heifer is in heat

Producer Question from 2012

Q.  I would like to know how I can determine when my heifer is in heat. And, if any symptoms what are they? (May 15, 2012)

A.  About 8 to 10 hours before standing heat (estrus), the female coming into heat will:

  • stand and bellow
  • smell other cows
  • attempt to ride other cows, but she, herself will not stand to be ridden
  • vulva will be moist, slightly red and swollen and may have some clear mucus discharge

When the female is in heat (estrus), she will:

  • stand to be ridden
  • bellow frequently
  • be nervous and excitable
  • rides other cows

The key sign is that the female coming into heat will "stand" and be ridden. This will last anywhere from 12 to 18 hours with a range of 8 to 30 hours.

Remember that ovulation in beef females does not occur at the time of standing heat (estrus) and will occur 12 to 18 hours after the end of standing heat.

To detect cows in heat, check at a bare minimum of twice each for at least 20 to 30 minutes each time. Most producers will check in the early morning and then later in the evening, when it cools off. The more often you check the better you will be at determining which cows are coming into heat.

Dr. Rick RasbyDr. Rick Rasby, Professor of Animal Science
Animal Science, University of Nebraska - Lincoln, Lincoln, NE