Which is right for your operation?
Pregnancy detection in cattle herds gives producers valuable information to help them assess next steps for their operations. A female’s pregnancy status impacts culling decisions, determination of reproductive performance and selection of replacement females.
There are different ways to check for pregnancy in cattle herds. The most commonly used methods include rectal palpation, ultrasound and biochemical tests. Each method has its own pros and cons.
Rectal palpation
Rectal palpation is the traditional method used by a majority of cattle operations. A trained individual detects changes that occur with pregnancy through palpation of the reproductive tract through the rectal wall. “Rectal palpation is the old standard,” Paul Beck, Ph.D., Livestock Extension Specialist, Oklahoma State University, explained. “In my experience, most luck of determining pregnancy through rectal palpation occurs when the animal is three to four months pregnant.”
According to the University of Missouri Extension’s publication, Determination of Pregnancy Status in Beef Herds, written by Jordan Thomas, Ph.D., Scott Poock, DVM, and Emily Smith,
“Pregnancy can be identified as early as 35 days of gestation by skilled palpators, but prediction of fetal age is most accurate between 45 and 120 days.”
Experts advise utilizing the assistance of a veterinarian, veterinarian technician or other trained individual to check for pregnancy through rectal palpation. There can be complications if an untrained individual attempts rectal palpation. “Some say in the real early pregnancy results, if you do it wrong or are too rough on the early pregnancy, you can cause the termination of pregnancy,” Beck explained.
Drawbacks to rectal palpation include, fetal viability and fetal sex, cannot be determined through this method. In addition, a trained professional should be performing the rectal palpation, meaning producers need to schedule time with a veterinarian or other skilled individual.
Ultrasound
A method growing in popularity to determine pregnancy in cattle is using ultrasound technology. The use of ultrasound to determine pregnancy gives producers access to a variety of information about a pregnancy. “It takes a lot of equipment and training, but you can do earlier detection using ultrasound,” Beck explained. “And it is accurate. You can get an accurate estimate of the conception date.”
An ultrasound probe inserted in the animal’s rectum captures images of the uterus and surrounding structures. This method can detect pregnancy as early as 28 days of gestation.
According to the University of Missouri Extension’s publication, Determination of Pregnancy Status in Beef Herds, “Perhaps the greatest benefit is the amount of information provided, as ultrasound allows assessment of fetal viability, identification of reproductive or developmental abnormalities, determination of fetal sex and a more precise determination of fetal age and expected calving date.”
Biochemical Tests
A new process in determining pregnancy in cattle has started to catch on with more producers. Biochemical tests to evaluate a female’s pregnancy status are now being used by many producers.
The biochemical tests detect hormone patterns or proteins specific to pregnancy. “It is a test for a placental protein that is very stable in a blood sample,” Beck explained. “Usually if you can get a blood sample a month after you have pulled the bulls, you can get a pretty accurate estimation of breeding.”
Beck added there are some false positives that may be due to embryonic loss or false negatives that may occur if the animal is very early bred.
In some cases, the blood samples are sent to a lab to be analyzed and results are provided after several weeks. However, on-farm tests that provide immediate results are now on the market.
There are drawbacks to this method of pregnancy detection; biochemical tests do not give the producer information about the conception date (unless timing of test is done strategically), fetal sex or fetal viability.
