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Understanding the Importance of Pregnancy Detection

by Wyoming Livestock Roundup

Reproductive success is the key to profitability for cow/calf producers. The ability to monitor reproduction is important when making management decisions affecting the bottom line.

Many cattle producers check pregnancies following the breeding season in order to identify nonproductive (open) members of the herd or herd members which conceived late in the breeding season. Having knowledge of pregnancy status allows managers and producers the ability to make culling decisions and adjust management priorities moving forward. 

Still, pregnancy testing is an under-utilized tool. Only about 20 percent of cattle producers implement it in their operation. 

Pregnancy testing usually takes place in the late summer or early fall for most spring-calving herds around Wyoming. Pregnancies can usually be first verified around the 30- to 40-day mark, but accuracy of detection can be a concern at early stages with some detection methods.

In general, there are three methods of pregnancy detection. These methods include rectal palpation, ultrasound and blood tests. Each method has its own set of pros and cons. Many factors can affect the price of pregnancy detection, but typically costs range from three to six dollars per head for all methods.

Rectal palpation

A thin layer of tissue separates the rectum and reproductive tract in the cow/heifer. This allows for palpation to take place with low chances of causing harm to the fetus and the uterine environment. 

Rectal palpation is often considered the traditional pregnancy detection method. The key to success with this method is to have a skilled and experienced technician. A skilled technician can detect pregnancies as early as 35 days. 

However, accuracy and usefulness of this method are much greater in pregnancies at least 55 days along. Cattle must be restrained, but the process is usually quick, and results are confirmed on the spot. This method also allows for evaluation of reproductive organ health, infections, cysts and other potential issues arising during the pregnancy.


In recent years, pregnancy detection via ultrasound has become an increasingly used method. There are many benefits to using ultrasound technology. Pregnancies can be determined as early as 30 days post breeding. 

However, skill and experience of the technician is a requirement for accurate results, especially during early stages of pregnancy. Unlike other methods, accurate measurements of fetal age can be obtained easily. 

This information can be beneficial when developing management strategies for specific calving dates while identifying fertile dams which conceived early in the breeding season. Fetal sex can be determined 55 to 60 days post breeding and multi-calf pregnancies can be determined with ultrasound. 

A major disadvantage to using this method is the upfront costs of the ultrasound equipment which can be in the thousands of dollars.

Blood tests

If collection and handling protocols are followed correctly, blood tests are an extremely accurate method of pregnancy detection, even for pregnancies as early as 28 to 32 days. Turnaround on results is usually fast but can sometimes take up to a week to receive results. 

Highly trained technicians and specialty equipment are not required, but like other methods, cattle must be restrained in a chute for sample collection. A disadvantage is cows will need at least 75 days to fully eliminate hormones from their previous pregnancy. Testing sooner may result in false positive results.

Additionally, the age of the fetus and expected calving timeframe cannot be determined with blood tests.

Pregnancy detection

It is important to remember, pregnancy is fragile during the first 60 days. Regardless of the detection method used, embryonic losses can still occur during this time. Care should be taken to minimize stress and discomfort during early pregnancy to ensure viable pregnancies and reproductive success.

It is important to consult and have a good working relationship with a licensed and experienced veterinarian when dealing with pregnancy testing. Operational goals should be discussed ahead of time to determine the correct method and timing of detection. 

Some operations have opted to become trained themselves and have taken steps to purchase the necessary equipment to closely monitor their own herd’s reproductive health and productivity.  

Regardless, putting emphasis on detecting pregnancy can make a big difference in profitability and management efficiency of cow/calf operations.

Chance Marshall is a University of Wyoming Extension educator based in Fremont County. He can be reached at cmarsha1@uwyo.ed or 307-332-2363. 

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