Skip to main contentSkip to main content
You have permission to edit this article.

Can early pregnancy detection help you make culling and replacement decisions this fall?

Early pregnancy detection.jpg

The earlier a cow or heifer can be identified as pregnant or open allows managers to make decisions on keeping, selling or even re-breeding females.

The long, hot days of summer are a stark contrast from the cold nights of calving season.  However, now is the time to start preparing for the arrival of the 2023 calf crop.  August or September is a prime month for ultrasound pregnancy diagnosis of your cow herd.

Value of Pregnancy Detection

As many producers are thinking about culling and replacement decisions this fall, one management strategy that should be considered for late summer/early fall would be pregnancy detection.

The earlier a cow or heifer can be identified as pregnant or open allows managers to make decisions on keeping, selling or even re-breeding females.

Pregnancy detection via rectal palpation can be determined as early as 35-45 days, whereas ultrasonography can determine pregnancy as early as 30 days.

One alternative could be implementation of blood tests which have been proven to accurately detect pregnancy as early as 28-32 days.

Advantages of Early Detection in Heifers

Heifers who are identified as open can be managed differently than their pregnant counterparts. Operations that utilize reproductive technologies, such as artificial insemination (AI) and embryo transfer (ET), have the advantage of knowing breeding dates.  This information can be used to schedule early pregnancy diagnosis with your veterinarian.  The following example follows dates for artificially inseminated heifers exposed to a clean-up bull for 60 days.

Heifers AI date: May 15

Bull exposure: May 20 – July 15

Ultrasound date: August 15

Calving dates: February 21 – April 23


During the ultrasound, heifers can be identified according to which cycle they were bred.  Heifers bred via AI will be approximately 90 days gestation whereas bull bred heifers will be between 30-65 days gestation.

Separating the cow herd by calving dates allows producers to create feeding groups with similar nutritional requirements.  It also decreases calf health risks by segregating calves by age.  This technique, known as the Sandhills Calving Method, decreases the pathogen load exposure on newborn calves. If retention is not the plan, bred heifers’ marketability increases with a known calving date and potential fetal sexing. Successful fetal sexing has been reported from 50 to 120 days but should be determined by experienced veterinarians.

Another benefit of early pregnancy diagnosis is identification of open heifers. 

Open animals can be moved from valuable feed sources and sold in a historically higher August-September cull market.

Non-pregnant heifers can continue to put on weight and can enter the yearling or feeder market.  Options to re-breed open cows for a fall or late summer calving group or if feed resources allow, feeding out open cows or grazing them on corn residue may be an option. 

Potential Disadvantages of Early Pregnancy Diagnosis

Keep in mind that rectal palpation and ultrasound does take time and gaining experience can have a long learning curve for inexperienced technicians.

Producers should realize that stress to heifers and cows early in pregnancy can result in embryonic loss.

Research has shown that heifers pregnancy checked at 42 to 74 days by ultrasound or rectal palpation resulted in an overall loss of 1.55% and ranged from 1-3.5%.

The blood test includes a moderate cost to ship and test samples as well as a five to seven day turn around for results.

Therefore, this method would not allow for sorting, separation, or replacement assessment on the spot when working cattle.

Additionally, determining stage of pregnancy would not be an option if you are considering this method.

Taking advantage of ultrasound pregnancy diagnosis can increase profits by decreasing unnecessary feed costs and reducing calf health problems. 

Having an idea of when your heifers will calve has the potential to prevent a few sleepless nights – which is priceless.   



* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Related to this story

Most Popular

Has the decision been made for when the last cutting of alfalfa will happen? This year it might not be an easy decision.

The ranch did something just a bit different the last 6 weeks and hosted a young lady from Switzerland.  She came over as part of a program ca…

I am coming up on four months post hip replacement on my left hip and three months on my right hip, often I am asked how I am doing. My answer…

"Restless Cow Syndrome can be contagious and often is passed on through the sight of other cows, especially if the other cows seem to be more content."

Recently Listed

Find the equipment you're looking for

Get up-to-the-minute news sent straight to your device.


Breaking News