genetic russian roulette Laura Mushrush
Do you want to put a bull of unknown genetic potential on your replacement heifers? The consequences could be devastating, say geneticists. By using all the tools that science makes available in tailoring your genetic selection criteria to your genetic goals, you can advance your operation more quickly.

Don't play Russian roulette with your cattle genetics

Cow-calf producers who don’t use science when selecting genetics may find their herd on the wrong end of a smoking gun.

A herd sire packs a powerful punch when it comes to the genetic development of a cow herd. An elementary school science lesson and plain common sense teaches the 50:50 relationship when it comes to the creation of offspring — take that logic to the cow pen, and a bad bull = bad calves.

However, with years of brain power invested into research and the development of technology, cattle producers have access to the most advanced genetic selection tools of their time, and those tools are right at their fingertips. Even still, there are producers hesitant to embrace the use of science when it comes to purchasing their next herd bull. According to Larry Keenan, director of breed improvement for the Red Angus Association of America, this resistance is as risky as playing a game of Russian roulette with your genetic program.

“The quality of a bull will be represented in the entire calf crop, because if his genetics are low-quality, then half of his offspring’s genetics will be low-quality,” Keenan says. “Making matters worse, it has a compounding effect that will stay in herd for generations if replacements are kept.” Reason being since you cull bulls more quickly than cows, your bull battery accounts for 75% of your total herd genetics.

6 bullets: Sale barn bull

A cow-calf producer is at the local sale barn to drop off some cull cows when a nice looking 2-year-old black bull enters the ring. Needing a new herd sire to put on his older commercial cows, he tips his hat until he buys the bull right above kill value. The following calving season is a disaster, with a 60% calving difficulty rate, two C-sections, a dead cow and three dead calves from calving problems, and one 145-pound calf that has become the talk of the neighbors.

While the above is part of a worst-case scenario of what can happen when producers buy a bull with an unknown background, the practice is surprisingly common. Maybe it’s in an effort to get a good deal, or the belief that simply eyeballing is good enough, but it can come with some pretty heavy consequences.

“The risks are multifold,” says Matt Spangler, a geneticist and Extension beef specialist for the University of Nebraska-Lincoln. “For one, you’re compromising your operation’s biosecurity since you have no idea what potential disease risks there are,” he says.

For example, when genetics are purchased directly from a seedstock provider, the purchaser will have access to knowing if the breeder tests cattle for persistently infected (PI)carriers of bovine viral diarrhea. And while there is a long-standing argument about the ethics of PIs being dumped back on the market through local sale barns once detected by cow-calf producers, backgrounders and feedlots, it is not a risk worth taking by potentially bringing in significant future health issues to a herd.

“Secondly, you have no idea if the bull is even fertile, or if he’ll pass a breeding soundness exam,” Spangler says. “You also have no idea what his genetic potential as a parent is. He’s nondescript in terms of having any kind of an EPD [expected progeny difference] or economic index value to choose from. All of those things become uncertain. Even though the bull may be much cheaper, it could be a very expensive decision to make if he happens to be diseased, unfertile or counterproductive to the rancher’s goals.”

1 bullet: EPDs

As sale catalogs start to come in the mail, a commercial cow-calf producer finds a seedstock operation with bulls that best fit his feeder calf program; and when sale day comes, he sorts through lots with a balance of EPD and physical conformation.

At the end of the day, he loads up a high-growth bull with EPDs signaling heavier calves, along with a second bull with more moderate growth and greater calving-ease-direct numbers. When breeding season comes, he turns the high growth, heavier-calving bull out with mature cows, and puts the calving-ease bull on his replacement heifers. Calving season brings no difficulties, and that year’s calf crop performs well in the feedyard and on the rail.

Simply using EPDs to compliment his program was a significant enough increase in genetic selection accuracy to remove five bullets from the chamber.

However, to capitalize on EPD accuracy, genetic buyers need to ignore raw data that may be available to them, such as the actual birth weight, weaning weight and yearling weight.

“If you’re looking at a bull with a 700-pound weaning weight and a 75-pound birth weight, you have no idea what the environmental contribution was,” Keenan explains. “Did you factor in that the bull was out of a 2-year-old heifer, which we know have lighter-weight calves simply because of the challenges she faces? And how did he reach that 700-pound weight? Was it from creep feed or was it genetics?”

According to Keenan, EPDs are designed to take raw data collected by the seedstock producer, and put those numbers through a series of complex equations to allow for comparison across herds throughout the country, by sorting out environmental impact from genetic potential.

“The only thing an actual or adjusted weight will do is to let you go to the coffee shop and brag about what your bull weighs, because the actual or adjusted weight only describes what the bull has done,” Keenan says. “But if you want to brag on how heavy your calves were and select for a future calf crop, then you need to select based off EPDs.”

Commercial bulls are another thing cow-calf producers need to be aware of. Depending on the breed association and if it has an open herd book or not, cattle with genetic information on one side of their pedigree may be registered and receive EPDs. However, because 50% of the equation is missing, these EPDs are lower in accuracy compared with EPDs with known parentage on both sides — but higher in accuracy than referencing actual weights.

“In recent years, we have seen a few commercial bulls make their way onto the market,” Keenan explains. “The risk with this is that EPDs only account for what we know about the sire. So if the dam happens to have an extremely low calving-ease direct, the producer could potentially be using an unknown cow killer.”

Empty gun: genomically enhanced EPDs

While EPDs are subject to change as a bull matures and becomes a proven sire, they still remain a foundational tool to make selection decisions, explains Keenan. But with the recent availability of DNA tests for genetic merit being on hand for cow-calf producers, yearling bulls now have similar accuracy values as if they have already sired offspring, increasing the pace at which producer can make genetic progress when EPDs have been genomically enhanced.

“If we think about genomically enhanced EPDs, ‘enhanced’ says all we are doing is adding an additional source of information to the mix of our traditional EPDs to allow us to gain more accuracy earlier,” Spangler adds. “The benefit is faster genetic change. And if animals are used that have higher accuracy at a younger age, then that is when herds can start to make faster progress.”

Using the tools in the toolbox

If a producers want to reduce the risk of having bullets in the chamber, it comes down to using all the selection tools available to them.

“As a commercial producer, I buy bulls from seedstock suppliers that are using every available tool at their disposal to ensure that the bulls are genetically described as accurately as scientifically possible. DNA tests for genetic merit are powerful tools, but we should realize that the foundation of accurate EPDs will continue to be quality data collection taken on the entire herd” Spangler says. “The combination of quality data and DNA tests will absolutely reduce my risk.”

 

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