When we talk about improving beef cattle genetics, it's easy to get caught up in the numbers. We want heavier calves, better growth, improved carcass merit and more productive cows. But there's another question we need to ask: Are we selecting cattle that fit the environment we're asking them to perform in?
Genetic potential is only part of the equation. An animal's phenotype, or how they perform, is a combination of their genotype and environment in which they are raised. Therefore, environment and management influence how that potential is expressed, and genetics that work well in one production system may not be the best fit for another.
In my conversations with producers, I tend to come back to three traits that deserve more attention when matching cows to their environment:
mature cow size, hair shedding and calving ease. Each addresses a different challenge, but all three provide opportunities to make more intentional selection decisions.
Mature cow size: Bigger isn't always better
The first place I encourage producers to look is mature cow size.
The industry has a strong incentive to produce heavier calves because we get paid by the pound. Larger cows often wean heavier calves, but individual calf weight doesn't tell us the whole story. Larger cows also require more feed to maintain themselves, which affects how many cows an operation can support.
The cow-calf phase accounts for approximately 74% of the total feed required to produce a pound of carcass weight (Rotz et al., 2019). Research has estimated that a cow that is 30% larger may consume 22% to 28% more forage dry matter daily (Beck et al., 2016). That additional demand matters, particularly when forage is limited.
Consider an example comparing moderate-sized cows averaging 1,100 pounds with larger cows averaging 1,400 pounds. The larger cows wean heavier calves, but the operation may not be able to run as many of them on the same amount of land. In the example presented by Doye and Lalman (2011), stocking 100 moderate-sized cows resulted in 12,000 pounds of additional calf weight from the 24 extra weaned calves (500 lbs x 24 calves) compared with only 76 larger cows able to be stocked on the same pasture space weaning only 7,600 pounds extra weight (100 lbs x 76 calves) due to "being larger".
That's an important distinction. We can improve total pounds weaned without necessarily increasing mature cow size. I'd rather have a moderate sized cow that weans a larger percentage of her body weight.
That doesn't mean the smallest cow is always the best cow. Mature cow size is an intermediate-optimum trait, meaning there can be disadvantages at either extreme. Recommendations for average mature cow size often fall around 1,100 to 1,200 pounds, although the appropriate target depends on an operation's resources, management and breeding objectives.
The goal isn't to select smaller cows simply because they're smaller. It's to understand what your resources can support and select cattle that allow you to make the most of those resources.
Hair shedding: A clue about environmental adaptation
Another trait worth paying attention to is hair shedding.
Hair shedding is particularly relevant for cattle expected to perform in environments with substantial heat and humidity. Cattle that retain their winter coats later into spring may have a harder time coping with heat stress than cattle that shed earlier.
The encouraging part is that hair shedding is moderately heritable, with reported heritability estimates ranging from approximately 0.32 to 0.41. That means genetic selection can influence how quickly a herd sheds its winter coat over time.
Hair shedding can be evaluated using a five-point scoring system. A score of 5 represents an animal that has shed none of its winter coat, while a score of 1 represents an animal that has completely shed its winter coat and has a smooth, short summer coat.
Research has also found relationships between hair shedding and performance. Earlier-shedding cows have tended to wean older, heavier calves. Data presented have shown approximately 11 pounds of weaning weight difference per hair-shedding score, or roughly 45 pounds between scores of 1 and 5.
Those results don't guarantee that changing a hair-shedding score will add a specific amount of weight to every calf. However, they reinforce the value of considering how cattle respond to their environment when making selection decisions.
Hair shedding is one more trait that can be incorporated into a breeding objective rather than treated as an afterthought.
Calving ease: Select for the outcome you want
The third area is calving ease, and this is where I often encourage producers to rethink how they use the information in a bull sale catalog.
When the goal is fewer difficult births, particularly in first-calf heifers, it's tempting to focus on birth weight. After all, lighter calves are often assumed to be easier to deliver. But selecting for low birth weight alone doesn't guarantee calving ease.
Birth weight EPDs estimate genetic differences in calf birth weight, expressed in pounds. Calving Ease Direct (CED) EPDs estimate genetic differences in the probability of calves being born unassisted when out of first-calf heifers. Calving Ease Maternal (CEM) EPDs estimate genetic differences in the probability that a bull's daughters will calve unassisted as first-calf heifers.
Those are different traits, and the distinction matters.
The genetic relationship between birth weight and calving ease is not strong enough to treat them as interchangeable. In the published literature, the genetic correlation between CED and birth weight was approximately 0.33, while the correlation between CED and percentage of assisted births was approximately 0.91. In practical terms, selecting for lower birth weight does not ensure that you're selecting for the outcome you actually want. Putting too much emphasis on producing lighter calves can also compromise growth potential.
Instead, start by identifying the problem you're trying to solve. Are difficult births occurring in first-calf heifers? Are mature cows also experiencing problems? What do your calving records tell you?
Then use the appropriate genetic information to address that problem. Calving-ease genetics can help producers select for unassisted births while maintaining moderate birth weights and desirable growth potential.
As with any trait, the goal isn't simply to maximize an EPD. It's to select cattle that fit the needs of the operation.
Don't overlook the breeding system
Matching genetics to the environment also means thinking beyond individual traits. Crossbreeding can be an important tool for improving whole-herd productivity, particularly for traits such as fertility, health and longevity.
Research by Gregory and Cundiff (1980) found that crossbred cows raising crossbred calves weaned 23.3% more calf weight per cow exposed than straightbred cows raising straightbred calves. Approximately two-thirds of that improvement was attributed to the crossbred dam, with the remaining third attributed to the crossbred calf.
That matters because reproductive performance and cow longevity influence how much productive output an operation gets from the resources invested in its cow herd. A breeding system should complement the environment and production goals, not work against them.
Start with the environment
One of the most important things we can do as cattle producers is evaluate performance in the context of the environment where it occurs. A calf's weaning weight matters, but so does the number of cows it takes to produce those pounds. Hair shedding matters because cattle have to function in the climate where they're expected to thrive. Calving ease matters, but so does maintaining the growth and performance we need in the next generation. These decisions are connected, and there isn't one ideal set of genetics for every operation.
Start by defining your production environment, identifying your limitations and deciding what you need your cattle to accomplish. Then use genetic information to select animals that fit those objectives.
Because the goal isn't to raise the biggest cow, produce the heaviest calf or maximize every number in a sale catalog.
The goal is to build a productive, efficient cow herd with genetics that work for the environment—and the business—those cows are expected to thrive in.
