Early pregnancy testing can improve efficiency of beef herd
Beef producers can use early pregnancy testing as a tool to sort and market their cattle, allowing them to obtain the highest and best value, according to a University of Nebraska Extension Specialist.
“Knowing when cows will calve helps the rancher to strategically manage his inputs,” said Aaron Berger, who recently presented a webinar on early pregnancy testing.
Looking at long-term averages, Berger said data shows that historically, cull cows are worth more between late-May and August, before prices begin dropping off significantly in September and October. If producers can early pregnancy check their cows, they can cull and sell the open cows when the market is higher and save feed costs by eliminating non-productive animals from the herd.
Berger said producers can open up new marketing opportunities for heifers by pregnancy checking those animals earlier, too.
If the bred heifers are sorted by early- and late-calvers, later-calving heifers can be sold into another producer’s program where the calving season fits better. By identifying open heifers earlier, those animals can be sold as yearling market heifers, capturing more value for the rancher.
Preg checking options
Producers can utilize three methods of early pregnancy checking – palpation, ultrasound and blood testing.
“Producers have to decide which method to use based on what tools they have available to them,” Berger explained. “They may also want to consider which method will give them the most return for dollar invested.”
“In some cases, a combination of methods may be the most time and cost effective,” he added. “Some producers may also want to use one method for cows and another for heifers for marketing purposes.”
The most common method is palpation, which is done by an experienced veterinarian or technician at 35 to 45 days post-breeding.
“Pregnancy can be identified as early as 35 days, but more realistically, it is usually 50 to 60 days for some technicians to accurately identify a pregnancy,” Berger explained.
Some producers like the palpation method because the results are known immediately, and producers can sort cows right out of the chute.
“There is no special equipment needed, but I would encourage producers to follow Ronald Reagan’s saying ‘trust, but verify.’ There are situations where the cow or heifer could be early enough into their pregnancy that the veterinarian or technician can not detect it through palpation. The producer may want to use a backup method like a blood test to make sure those cows or heifers are really open. A pregnant cow or heifer is worth more than an open one, even if they are late,” he noted.
Berger also warns producers that having the cattle palpated can cause them to abort.
“Generally, it only happens about one to three percent of the time, based on pregnancy age and the experience of the technician,” he explained.
A less invasive method is ultrasound, which can detect pregnancy as early as 28 days after breeding.
Berger said producers who use ultrasound can still sort their cattle straight from the chute but can also sort the cows based on age of the fetus, sex of the fetus and whether or not the cow is expecting twins.
“If a producer has a high number of cows expecting twins, they may choose to sort those cows off and feed them better to save more of the twins at calving time,” he explained.
“Producers can also sort cows and heifers based on when they calve to group the calves up tighter,” he added. “Ultrasound is the most informative pregnancy diagnosis tool we have available right now.”
Less expensive options
Producers who are only interested in whether or not the cow or heifer is pregnant may choose blood testing, which is generally the cheapest pregnancy testing method but also the least informative.
“The rancher can pull blood and send in a sample to a lab for about three to five dollars a head,” Berger said. “Blood testing can identify pregnancy as early as 30 days by searching for pregnancy-associated proteins that a cow or heifer will have present in her body.”
“The test is 99 percent accurate for identifying open cows and heifers and 95 percent accurate in identifying pregnant cows and heifers because some animals early in pregnancy will naturally lose the pregnancy,” he explained.
Although blood testing is less invasive and allows the producer the flexibility to pull blood samples over a number of days, the turnaround time for the test is two to four days, so the cows will need to be resorted after the test results come back.
Berger also cautions that cows need to be at least 90 days post-calving or false positives may occur. The test only identifies if the cow is pregnant, it can’t identify the age of the calf to determine if the cow is an early- or late-calver, he added.
Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to firstname.lastname@example.org.