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Producers should consider breeding system and environment when selecting genetics

by Wyoming Livestock Roundup

For most commercial cattlemen, buying new genetics or undergoing a change in genetics is usually the result of sire purchases. In fact, according to Sean McGrath of Round Rock Ranching, roughly 75 percent of new genetics on commercial operations come through the purchase of a bull.  

“When we go out and purchase new genetics, in most cases through bulls, we are really just purchasing DNA to fit into our environment and our breeding system,” McGrath says during the Beef Cattle Research Council’s breeding goals webinar dated Feb. 17. 

McGrath is one of two speakers in the webinar and spends his allotted time discussing the importance of matching breeding goals to an operation’s environment and breeding system.  

Long and short-term goals 

First, McGrath mentions the difference between some long and short-term goals in regards to a breeding system, although he notes the majority of these decisions should be focused on the operation’s long-term goals.  

“An example of short-term priorities in a breeding system might be calving ease considerations in sire selection,” McGrath explains. “If I go out and buy a bull to use on my replacement heifers, I want one with a good calving ease expected progeny difference (EPD) because I don’t want to be out helping my heifers calve all spring. This is a short-term goal.” 

McGrath continues, “One of the biggest challenges with beef cows is the amount of time it takes in terms of reproduction. In fact, cows bred this year won’t calve until the spring of 2022, and we won’t wean these calves until the fall of 2022. If we keep them as replacements, they won’t be bred until 2023, and they won’t calve until 2024.” 

Because of this, McGrath emphasizes the importance of long-term planning when making sire selection decisions. He also notes considering how cattle will be marketed five to 10 years down the road is another important aspect of long-term planning.  

Reproduction, production and carcass 

McGrath notes one of his favorite pieces of Extension work, conducted in 1995, splits beef production into reproduction, production and carcass.  

“The data shows in a traditional system – breeding cows, weaning calves and selling them off in the fall – reproduction is nearly five times more important to a producer’s decision making and profitability than production and 10 times more important than carcass,” he explains. 

For producers participating in a value chain, McGrath says data shows reproduction is twice as important as production and carcass, and for those in an integrated system, carcass is twice as important as reproduction and production.  

“Genetic priorities are different for different operations, and it is important producers are emphasizing and selecting on the priorities that fit their particular needs,” states McGrath.  

Genetic potential and the environment 

Additionally, McGrath explains a cow’s genetic potential has a lot to do with the environment they are in, especially in terms of feed availability and relative stress level. 

“If a herd has a lot of available feed and they live in a low-stress environment, they will excel in different traits, such as milk production, they will generally be bigger, and they won’t need a lot of body reserves because all of their energy is supplied in their ration,” he says.  

“On the other hand, cows in tougher situations – less available feed and more relative stress – are not able to support large gut and organ mass and high milk production all while rebreeding and maintaining a pregnancy,” he adds. “As far as breeding systems go, producers should be looking for dam and sire crosses that will produce offspring with the proper traits to excel in their particular environment.”  


Another breeding system advantage, according to McGrath, is that of heterosis through crossbreeding.  

“One of the things many producers lose sight of in their breeding systems is heterosis,” he states. “By taking advantage of crossbreeding, producers can see higher survival rates, higher calving weights and increased birthweights. Work done at the U.S. Meat Animal Research Center shows a 16-pound advantage in a cross-bred calf over a straight-bred calf.”  

In addition to offering heterosis, McGrath also points out maternal heterosis can be advantageous, noting the benefits of a cross-bred cow over a straight-bred cow ultimately amounts to weaning an extra calf over a cow’s lifetime. 

“When picking bulls to improve herd heterosis, producers need to not only consider complementary breed traits, they also need to keep similar genetic profiles in mind,” says McGrath. “This will not only allow them to utilize heterosis, it will also weed out a lot of inconsistencies some producers see in crossbreeding systems.”  

Selecting new genetics 

When it comes to choosing sires, McGrath believes looking at herd records is a good place to start, as they speak volumes about an operation.  

“One good record to take a look at is calving distribution. This will tell a producer a lot about their ranch and how their genetics fit into their environment,” he explains. “If the majority of calves on an operation are born in the first 21 days it means the herd is rebreeding quickly and fitting well into their environment. But, if producers notice a change in this distribution, it may mean their genetics aren’t fitting well.”  

McGrath also says financial information and profit margins can help a producer understand if their breeding system is working and encourages producers to look back at information on sires they have bought in the past. 

“Producers should look at the EPDs of bulls that have worked well in their system and their environment, then go out and buy more bulls with similar numbers,” he explains. “They should also look back at information on bulls that did not work to avoid buying bulls like this again.”  

He continues, “Most importantly, producers need to take some time to understand what their operation looks like – the feed resources they have available, their calving season, their labor resources, if they plan on keeping replacements, when they sell, what they sell and how they sell. These are all really important considerations when choosing genetics to fit the goals of their operation.” 

Hannah Bugas is the editor of the Wyoming Livestock Roundup. Send comments on this article to 

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