Early Pregnancy Testing In Cattle Can Now Accurately Age Fetus And Determine Gender
MT. VERNON, MO.
Beef producers who participate in the Missouri Show-Me-Select Beef Heifer Development Program are required to have heifers pregnancy tested no later than 90 days into the pregnancy.
“The primary reason for the early preg test is to age the fetus more accurately. This is how the expected calving date is established,” said Eldon Cole, livestock specialist with University of Missouri Extension. “It also enables the veterinarian to distinguish whether the fetus was the result of artificial insemination or by natural service from the cleanup bull. Of course, there must have been a 14-day lapse from AI to the natural service exposure to make that call.”
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Veterinarians prepare for fetal aging and sexing instructions.
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Dr. Scott Poock (center) holds the monitor while veterinarians await the call, bull or heifer.
ULTRASOUND
An increasing number of veterinarians in southwest Missouri have enhanced their fetal aging ability by the use of ultrasound. A few veterinarians can be as accurate using palpation, attaining in the 90 to 95 percent range, based on actual birth dates submitted by buyers of the SMS heifers sold in the sales.
“One feature the ultrasound can provide that palpation cannot is the ability to sex the fetus. This capability has been known for several years, but we’ve not had enough experience with heifers carrying known calf sex to see how the market reacts to that knowledge,” said Cole.
During this period of herd expansion, Cole says conventional wisdom has been that heifers carrying a heifer calf would command extra bidding. However, that bull calf could still easily outsell the heifer calf at weaning due to its extra weight and normal $6 to $10 per hundred price.
“This would help return a quicker return on the investment. Another plus for heifer calves would be less likelihood of calving difficulty,” said Cole.
VET TRAINING
Seven veterinarians who work with SMS cooperators in southwest Missouri, recently met at the Animal Clinic of Diamond to sharpen their skills on the use of ultrasound. Dr. Scott Poock, a University of Missouri Extension veterinarian, was the instructor. Cole says that Poock is especially good at teaching fetal sexing when the fetus is in the 65 to 85-day stage.
“A side benefit of the morning was that most of the veterinarians brought their ultrasound equipment. After they had worked with the different units one veterinarian was convinced to invest in a better ultrasound unit,” said Cole.
Over 100 heifers that had been AI bred on Nov. 3 were used for the training session.
“Some of these will likely end up selling in the May 15, Show-Me-Select Bred Heifer Sale with the sex of the calf they are carrying reported,” said Cole.
Those interested in learning more about the Show-Me-Select Bred Heifer Sale can attend a meeting at the Lawrence County Extension Center in Mt. Vernon at 7 p.m. on Feb. 16. ∆