Longevity vs. fertility in the cowherd
June 14, 2012
More longevity and fertility in the cowherd seem like a “no brainer.” But when those pursuits come at the expense of uniformity or other functionality, it could pay to do some hard studying.
“The overwhelming cost and subsequent priority of cow-calf operations is related to cow maintenance and care,” said Nevil Speer, an animal scientist at Western Kentucky University. “The difference is huge between a cow that lasts until she is 10 versus 8.”
That’s why crossbreeding is the default, blanket prescription for commercial cattlemen looking to make reproductive improvements.
But South Dakota rancher Rich Blair says, “Been there, done that, and don’t want to go back.”
He and his brother Ed turned their once-straightbred Herefords into Continental crossbreds in the late 1970s and ’80s, but gradually phased that out in the ’90s when the family turned its focus to Angus.
“We always calved out quite a few first-calf heifers and you’d lose or cull 25 percent of those for one thing or another: disposition, udders, no milk, mothering ability,” he said. “Now we’re closer to 2 percent and we have a lot more consistency in our heifers.” He gives most of the credit to the breed association’s extensive database and the use of high-accuracy sires.
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Heartland Cattle Company, near McCook, NE, custom develops heifers for a large number of commercial Angus herds, and also sells bred heifers by forward contract. Many long-term heifer buyers say they want that hybrid vigor in black baldies, but those have been hard to come by.
Comparing the two sets of females, research and information director Janet Rippe says they’re fairly similar.
“Our first service conception rate is averages 71 percent and then after a 45-day [artificial insemination, AI] season, we’ll send heifers out of here at about 91 percent to 92 percent pregnant,” she said. “If you get a true hybrid or an F1-cross or even just a quarter something else, those cattle are generally more fertile. But we might not see as much difference in the numbers because our long-term Angus customers have put so much selection pressure on fertility.”
All are subject to pre-breeding inspections that include pelvic measurements and reproductive tract scores, and outliers exit the program then. Customers may opt to market “recommended culls” that fall out for things like disposition, too.
“What’s left should be pretty functional,” Rippe said.
Regardless of who is growing the replacements, all cattlemen have their initial priorities. According to USDA data, 62 percent of ranches sold cows for reasons other than just being open. Studies point to some of those reasons.
“The 2010 BEEF survey reveals that disposition, birth weight, hoof and leg soundness all ranked above weaning weight and yearling weight in terms of genetic prioritization among commercial producers,” Speer said. “In other words, time savings has more value than additional weight or production.”
Blair now relies on expected progeny differences (EPDs) within the breed because, he said, “I don’t have time to deal with calving problems.
“Hard births cause a multitude of problems,” he said. “It isn’t just if that heifer had a hard time and you had to pull that calf, but now you wonder if she’s going to breed back and if that calf is going to be healthy.”
On the other hand, in a large herd with focused management, predictably shorter gestation periods from high-accuracy EPD bulls can allow a couple more weeks for heifers to breed back, Blair says.
Although no producer invites challenges, Speer says the issues become increasingly important as herds get larger.
“I have an additional benefit from heterosis, but if it costs me something in terms of functionally of traits, such as calving ease, I don’t want to have to deal with those problems,” he said. “That risk/reward becomes somewhat different when you put all of those factors in together.”
Everybody seems to agree that it’s a hard area to quantify.
“With fertility there are so many factors: was it weather, was it the technician, was it the bull, was it the sire line that came into it?” Rippe said, “It’s pretty hard to get good enough data when you’re looking at fertility.”
Adding in longevity multiplies that difficulty.
“It’s a lot more complex than just reproduction,” Speer said. “Why else did she leave the herd? A bad eye, a structural soundness problem, disposition or all those other things you can readily select for?”
Those who are making steady progress in any number of traits may not place as much importance on longevity because of the reduced opportunity to make genetic change.
Blair remembers a particular bull they used a decade ago with a then-impressive Angus EPD of 0.4 for intramuscular fat (IMF). “That was really out there in 2000, and one of the big reasons I used him was for that number,” he said. “Now you can find hundreds of bulls that are 0.4 IMF.” In fact, that’s about breed average today.
Longevity in outstanding individuals helps a program but across the herd, it may not be the highest calling. “If you’re not turning that cowherd over, it’s really hard to get much genetic improvement in your calves,” Blair said.
The Blairs have been using all Angus since feedlot performance data showed them the top end of those calves kept up with the top end of their Charolais calves. Figuring in maternal traits and labor savings, it was starting to look like another kind of “no brainer.” The deal clincher showed up when calves sold on the grid and they saw more than a $200 spread in value.
“That was too much money to be giving away, so we wanted to move the bottom end up,” he said.
Some Blair loads have hit 50 percent Prime, selling for $200 above average Kansas price for the U.S. Premium Beef grid for the week.
“Everybody looks for the silver bullet, the quick fix, with no time for a long-range plan,” Blair suggested. “If that’s your attitude then heterosis is the quick way to get there. But if you really want to build something sustainable over a long period of time, you can find the data within one breed and design the cow to be exactly what you want her to be.”