One step to building and keeping a productive cow herd is in replacement heifer selection. Using pre-breeding exams to help make decisions about which heifers should be kept or culled is a cost-effective way to eliminate potential problems.
Rachel Gray runs Little Timber Farms in Blackduck, Minn., along with her dad and son, raising replacement heifers. They utilize pre-breeding exams for all the heifers they market to other cattle producers. Gray worked with their veterinarian to develop several protocols when they switched from cow-calf to heifer development eight years ago to ensure they are marketing a high-value animal.
“Pre-breeding exams were not something that we did when we were strictly cow-calf,” Gray says. “Now I look back and I think, ‘Boy, we should have.’”
While it’s not fool proof, Gray says it’s her job to find the problems before they are her customers’ problems.
“I think we usually eliminate about 2% of our heifers with this pre-breeding exam,” she says. “Maybe that’s not a ton, but that’s phone calls that I don’t get at three in the morning because a calf is stuck in a V-shaped pelvis.”
With current cattle prices as high as they are, Gray says it makes financial sense to weed out any problems early as those heifers can then be marketed as feeder calves.
“I think the value is not having to spend any more money on an animal that’s not going to be a good producer to you,” Gray says. “Bottom line is, if you have something that is not working, maybe they only have one ovary, and aren’t going to get pregnant fast. Or if there’s something else where you can see ahead of time that a calf is going to get stuck in a pelvis, we all know that’s not profitable. Dead calves are expensive. When you can eliminate that problem on the front end, and sell that heifer as a feeder right now and get some profit, and then either buy back a heifer that works for you or put that money to something else that just really helps clean up that bottom line.”
Elizabeth Picking, field specialist in livestock, University of Missouri Extension, explains pre-breeding exams performed by a veterinarian can help producers identify later-maturing heifers. These exams should be done at around 12-15 months of age, prior to bull turnout or artificial insemination.
“To set that heifer up for lifelong success, she needs to reach puberty by 15 months of age to potentially calve at 24 months,” Picking says. “However, roughly 35% of heifers do not reach puberty by 15 months.”
“As the reproductive tract score increases, the heifer’s likelihood of becoming pregnant increases,” Picking says. “Heifers with a tract score 4 or 5 are already cycling and will have more opportunities to achieve pregnancy when out with a bull than a heifer who is a tract score 1 or 2 and may not be cycling when the bull is turned out. Further, pregnancy rates are lower on a heifer’s first cycle, so it is best to have a heifer already through her first cycle when she is artificially inseminated or turned out with the bull.”
Heifers who cycle early will also breed and calve earlier in the season.
“Because she calves earlier, she has more days to return to cycling again than later-calving cows in the same herd, and she is more likely to breed back successfully,” Picking says. “This trend generally continues throughout that female’s life, allowing her to produce more calves and be more profitable.”
Along with the reproductive tract score, a veterinarian can measure the pelvic area.
“By selecting for larger pelvic areas, producers can decrease the number of difficult births and death losses, improving their bottom line,” Picking explains. “Producers should consider culling heifers with a pelvic area smaller than 150 cm to avoid the risk of losing the calf or heifer when she calves for the first time.”
Little Timber Farms takes advantage of the pre-breeding exams to evaluate heifers for other culling criteria including bad structure and temperament, as well as giving vaccinations.
“Those animals are getting not only that internal score for their pelvis, how they are reproductively, but they’re getting a docility score. We’re looking at feet. Are we seeing any foot issues, or structure issues, things like that?” Gray explains. “The business is too important to put good cattle out there to breed the bad ones.”
Picking also recommends taking advantage of having the heifers in the chute to give them vaccinations for the following diseases to set them up for success.
• Bovine viral diarrhea (BVD).
• Infectious bovine rhinotracheitis (IBR).
• Bovine respiratory syncytial virus (BRSV).
• Parainfluenza 3 (PI3).
• Five common types of leptospirosis.
Gray says she understands some producers don’t do pre-breeding exams because they know their cow herd and bloodlines. But she says it’s a low-cost exam that could later save time and money.
“I would encourage people to do it even on your own heifers,” Gray explains. “Get a vet that knows what they’re doing and is willing to ultrasound. I’ve heard some people say they just use the pelometer or just measure. That’s a good place to start. But I think taking a look with the ultrasound is really important because you see things you wouldn’t have otherwise. We found cystic ovaries that maybe wouldn’t have bred. We can eliminate a lot of that problem. We get paid by the pound. We get paid by the calf, so we need to put big, healthy, good calves on the ground.”
Picking agrees.
“Performing pre-breeding exams on all replacement heifer candidates before investing more time and resources into breeding gives the opportunity to assess each heifer’s potential as a future cow and identify which heifers would be better in the feeder market,” she says.
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