Building Better Replacement Heifers | TSLN.com

Building Better Replacement Heifers

by Jeremy D'Angelo
for Tri-State Livestock News

Managing heifers is a double-edged sword.

On one hand, as the future of the cowherd, heifers are an important investment. However, due to their management needs and the two-year delay before they put a check in the bank, managers need every tool possible to make sure the heifers they're choosing are going to be a cost-effective addition to the herd.

One of the shiny, new tools in the toolbox is genotyping. Companies like GeneSeek now offer relatively low-cost DNA testing for heifers, which can be helpful for both commercial and seedstock producers, said John Paterson, territory manager for GeneSeek and professor emeritus from Montana State University.

Genomic testing heifers can add more data to selection decisions that have historically been based on looks. Genomic testing adds predictions about calving ease, birthweight, average daily gain and several other traits, depending on which profile the producer selects, in addition to confirming parentage. "Now you go out into 100 heifers and you can say, 'What are my top 25 heifers based on genomic testing? Now, do those agree with my eye?' It gives you a lot more information than you've ever had," Paterson said. "When it's so expensive to develop heifers, and the price of cattle has come down, you only want to keep the heifers that will make money for you."

Paterson says the test he recommends for most commercial herds involves creating an index with about 65 percent of the emphasis on maternal traits and 35 percent on growth and carcass traits. "We get ourselves into trouble when we select for single traits," he said.

The parental validation offers producers the information they need to make bull selection and culling decisions, Paterson said. "Say you've got three to four bulls out there with the cows. You go out in the fall and say, 'Man, I really like those calves. Who's the father of those calves?' Or you go out and there's a bunch of hairballs and you say, 'Man, who's the father of THOSE calves?' With multiple sires in a pasture you can decide which bulls are really working for you."

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Genomic testing allows producers to change the direction of their program more quickly. With traditional methods, it took four years to see the results of a breeding decision when developing heifers. Now, producers can have an educated prediction of the success of their heifer choices before the heifer even leaves the cow.

Eventually, those predictions could happen before a heifer is even born. "We're even talking about taking 10 cells off an embryo and predicting six years into the future," Paterson said. "That technology is being used now, they're just trying to validate it."

The technology has been around for a long time in the dairy industry, where most of the emphasis is on maternal traits. "It's really caught fire [in the beef industry] in the last five years," Paterson said.

Until recently, the testing has been fairly cost-prohibitive for commercial producers. Now, the testing starts at $15 for a parentage verification test, with a six-trait genomic prediction adding $10 to that figure. A full 13-trait panel costs $40, but Paterson said for most commercial producers the $25 test is sufficient. He recommends the 13-trait panel for only the heifers that look really outstanding on the six-panel test.

For seedstock producers, a full genomic-enhanced EPD is available. The genomic testing isn't designed to replace the existing EPDs, but the goal is to make them more accurate.

"We want more and more animals in the database," Paterson said. "The DNA is matched against actual data, so the more information we have, the more accurate we will be."

While the shiny, new tools offer some intriguing insight into what makes a heifer successful,

Bob Weaber, Associate Professor of Animal Sciences at Kansas State University, says when it comes to traits like cow longevity and fertility, genetics account for only 10 to 20 percent of variation in those traits, with management and environmental effects accounting for the vast majority.

That's why Matt Stockton, associate professor of agricultural economics at University of Nebraska Lincoln (UNL), says producers have to look beyond the numbers on a genetic profile, and consider the whole picture when making their heifer selections.

"You have to know the genotype relative to what you're managing and you've also got to understand the phenotype of what you're trying to manage as well." Stockton says.

Stockton says that, theoretically, the return on investment on genetic testing is worth it for some operations, such as seedstock producers, but whether or not to genotype heifers is dependent on the individual operation and the value the operation places on their genetics.

"DNA gentoyping is an added cost," Weaber says. "If you're going to genotype, make sure you know how and when to use the information to make a profitable decision."

Paterson agrees with that. "We can run DNA, but the producer has to know how to use that technology to make his cowherd more efficient or more profitable."

When it comes to future fertility, some research conducted by Rick Funston, UNL West Central Beef Reproductive Physiologist, has shown that traits such as cow age and birth date can indicate future fertility. For example, calves born during the first 21 days of a calving season had better pregnancy and breed back rates later on in life.

Weaber says that this is because heifers born earlier in the calving season reach puberty sooner and are therefore more likely to breed as heifers.

"Heifers that conceive their first calf early in the breeding season have a much higher chance of being reproductively successful as cows as they'll have more chances to breed [more estrus cycles during breeding season] than cows that calve late in the breeding season."

This is where proper record keeping, such as birth date, when the cows calve every year, and cow size, really comes into play when identifying replacement heifers, Funston says.

Galen Fink, owner of Fink Beef Genetics in Randolph, Kansas, believes very strongly in retaining replacement females out of the earliest calving cows because they generally are the most fertile cows.

"We do not utilize late calving females in our program, unless there is some legitimate reason to retain her," Fink says.

Ranchers should also realize the genetic impact that sires have on heifers and the future of the herd.

Funston has conducted research that has shown that 85 percent of genetic change comes from the sire.

"Probably the most genetic change is made on the sire side and contribution of any one female to overall genetics in a cow herd is very minimal," Funston says.

According to Weaber, this genetic influence of the sire can be capitalized on through the use of artificial insemination.

"AI can enable the investment of semen from highly proven sires for fertility and stayability traits to ensure the most productive, long-lasting cows," Weaber says. "This focus on 'cow' [type] bulls allows producers to build environmentally-adapted cows that fit their production environment in terms of mature weight and lactation potential."

Weaber says AI can also enable very structured crossbreeding systems that can be more easily facilitated through using AI instead of natural service sires.

Stockton encourages the use of AI on ranches because typically the cost is the same, or in some cases, cheaper, than natural service sires, different sires can be selected for different dams with AI, and producers can know for certain which calves are out of which bull.

Fink says he uses AI on 99.5 percent of his herd and has been using AI for over 36 years.

Adding sexed semen to an AI program can benefit seedstock producers who want all heifers or commercial producers who are looking to produce bulls for future feed lot steers, Stockton says. "We probably use more sexed semen than anyone in the U.S.," Fink says. "We use it to create more bulls."

"One of the challenges with buying 'cow' or very maternally focused bulls is that these bulls produce steer mates to the desired heifers," Weaber says. "Often these steers give up a lot, due to the antagonisms between growth and mature weight, in terms of growth rate, composition and pay weight compared to either dual purpose or terminal sires."

Essentially, by using sexed semen, producers can dramatically reduce the number of bull calves sired by maternally focused bulls, reduce the number of cows needed to produce replacement heifers, and increase the number of cows allocated to producing terminally sired calves for the market.

According to Weaber, producers should also be conscious about their operation's goals when making breeding decisions and consider separating maternal and terminal sire selection decisions.

For maternal sires, producers should focus on calving ease direct, optimal (not maximum) genetic potential for growth, and moderate levels of milk, Weaber says. For terminal sires, producers should consider selecting for as much growth as possible in a reasonable calving ease package.

"All of these are viable options, the question is what is the cost versus the gain," Stockton says. "They need to match their management to their cow type."