Category: EPDs

Comparing Cattle for Crossbreeding

Across-breed EPDs and the value of shared metrics

Imagine you want to buy a horse. But you’re a tall guy, so you want a tall horse. In your search, you find advertisements for two likely potentials. They both look like great ranch horses, but one is listed as 72 tall while the other is described as 132 tall.

If you chose based on those numbers alone, without knowing the measurement systems being used in each case, you would be short-changed if you chose the second horse because of its seemingly larger height number.

If you knew the measurement system each number was coming from—inches and centimeters, respectively—and knew how to convert those systems to make them comparable, it would be clear that the first horse is taller despite the seemingly lower number (72 in. versus 132 cm, a.k.a. 52 in.). If both horses were measured using the same system—let’s say, hands, making them 18 hands versus 13 hands—to begin with, it would make finding the taller horse even easier.

Expected progeny differences (EPDs) in the cattle world are a lot like our hypothetical tall horses problem. Most breeds’ EPDs are on different bases. An EPD basis is analogous to a measurement system; it’s the system in which their measurement numbers (i.e., EPDs) make sense. If you try to directly compare the weaning weight EPD on an Angus bull to the weaning weight EPD on a Hereford bull, for example, your success at getting a bull that meets your genetic goals will be about as successful as if you had chosen the second “tall” horse.

Avoid wrecks in breeding season

Burt Ruthrford – Beef Magazine

I have a confession. I’m not good with numbers. So, let’s talk about numbers. Selection indexes, to be exact.

Actually, Matt Spangler is going to do the talking. Spangler is a beef geneticist at the University of Nebraska-Lincoln and one of the speakers at a King Ranch Institute for Ranch Management lectureship on genetics recently in Denver. In addition to KRIRM, the symposium was sponsored by the National Cattlemen’s Beef Association and Colorado State University.

How many of you have taken up a bull sale catalog and, with expected progeny difference (EPD) thresholds in mind, circled bulls you’re interested in and crossed out the bulls that don’t meet one or more of your baseline EPD levels? Probably everybody.

But, Spangler asks, how many good bulls did you pass by because they didn’t meet one of your EPD thresholds, but excelled in others? The guilty need not come forth.

That’s where an index comes in. Indexes are easy to use and interpret — and most importantly, are economically driven. Traits get more weight if they’re larger drivers of profit.

Indexes inherently account for the genetic relationships among traits as well. That’s good. It can also be very bad if you use the wrong index.

“If you think about growth traits — mature cow weight, birth weight, weaning weight, yearling weight Avoid wrecks in breeding season — they’re obviously not independent. These early traits are not independent of mature cow weight,” Spangler says. “

That means if I select to increase weaning weight and I also keep back replacement females, there is a tendency over time that the heifers I’d kept back are going to be larger in terms of mature cow size,” he says. “I have now pitted revenue, weight of calf at sale or weaning, against cost, which is increasing the cow size and increasing maintenance energy requirements.”

Can you select for multiple traits? “That’s what a selection index allows us to do.”

If you’re a terminal breeder, selecting an index like the Angus $Beef or $B is exactly what you should do. “But there’s a whole lot of commercial bull buyers that don’t fit that, but they still use $B to rank bulls they buy,” Spangler says.

“And it’s inappropriate because of replacement heifers. Dollar beef will put a lot of emphasis on carcass traits, carcass weight.

And so, as a consequence, the heifers they keep back will tend to be larger at maturity.” And because it’s a growth index, it doesn’t take into account female fertility. So, as you gear up for bull sales this fall, study those indexes carefully and know what traits they take into account. ❚❚

Sorting Out the Bull

February 2015

Selecting a bull today can be an overwhelming task for many cow-calf producers. Photo courtesy of Aaron Berger.

The winter and spring bull sale season is well underway. For many cow-calf producers this is when catalogs are studied and sales are attended, with the focus being on the purchase of their next herd sires. The purchase of a bull is a significant investment and represents the genetic future of the calves and in many cases replacement heifers that will go into the cowherd. The following are thoughts on a process that producers can use when planning the purchase of their next sire.

What do you want your cowherd and the calves you produce to do? What genetics will do that?

Clearly identifying goals for what cattle are expected to do and the traits and characteristics that most impact profitability for the cow-calf enterprise is a foundational first step. Are calves sold at weaning, as yearlings, or is ownership retained through until harvest? What do the purchasers of your calves want? Can you produce what they want and have a functional female if replacements are retained? What is an optimum target given the production system cows are expected to operate under? These “big picture” questions should be answered prior to the selection and purchase of a bull.

Where is my cowherd at genetically?

“Wherever you are at, that is where you are.” Randy Hunter, DVM and stocker/yearling operator from Wheatland, Wyoming uses this phrase when teaching cattle handling skills to help people recognize everyone is at a different place in their ability. Once you know where you are, you can identify a plan to move toward where you want to go. This phrase applies well to thinking about the genetics of the cowherd. What is the genetic makeup of the cowherd currently? Are you pleased with where you are? What traits or characteristics would you like to see change? What is the target for where you want to end up? How much change is needed to reach an optimum level given your resources?

Sorting out the bull breeder

Selecting the breeder and breeding program of your next bull is more important than the choosing of the bull himself. The following are characteristics in no particular order that need to be considered when deciding who will be your genetic provider.

  1. Honesty and Integrity
  2. Custmer Service
  3. Genetic Program and Focus
  4. Bull Development Plan
  5. Value Added Opportunities

Sorting through all the information

Selecting a bull today can be an overwhelming task for many cow-calf producers. Bull sale catalogs are full of information, including actual animal performance, ratios, Expected Progeny Differences (EPDs), gene testing, economic indexes, ultrasound measurements, etc. There are also individual breeders who utilize their own scoring system for characteristics such as disposition and udder soundness of a bull’s dam. Having access to all this information is great. However, trying to sort through and discern what these data mean and which information is relevant to what you want can be a bit like trying to get a drink out of a fire hose! What you want is there, but you can find yourself getting smacked in the face with more than you wanted when you go to get it.

Know and understand what the numbers mean

The first priority is to know and understand EPDs. Research has shown EPDs are a tremendous and valuable tool for giving an indication of what a bull’s true breeding value is in terms of the genetics he will pass on to his calves. Understanding what the numbers mean and which ones are relevant for the traits which you are selecting for is important. Matt Spangler, University of Nebraska–Lincoln Extension Beef Genetics Specialist has put together a NebGuide titled “EPD Basics and Definitions” that explains what these traits mean and how they can be used to compare animals within a breed to one another. In most cases, EPDs are not comparable across breeds. An exception to this is Red Angus and Simmental EPDs which are a multi-breed EPD and are calculated in the same way.

Economic indexes are the second set of numbers to understand. Matt Spangler defines economic indexes as “A collection of EPDs weighted by their economic value such that traits with greater impact on production goals have a larger economic weight associated with them.” Understanding how different economic indexes are calculated for the breed you are evaluating can help you to know if they should be used as a tool for selection.

The third set of numbers to grasp and evaluate is an individual’s own records and performance against those of his contemporaries. These indicate how a bull did in his own right. While worth looking at and evaluating, they are secondary to EPDs for identifying a bull’s true breeding value.

Identify the bulls that meet your “numbers” criteria

Sorting through the bulls on paper and identifying those that meet your criteria is the next step. Plan to do this well in advance of the bull sale so you give yourself adequate time. The more stringent the criteria and the more values you include, the fewer bulls you will have to pick from.

Visually appraise bulls for structural soundness and phenotype

While a bull may look good on paper, when you actually see him, he may not be the type and kind that you want. Remember that this bull’s purpose in life is to get cows pregnant. That means he has to be able to move and cover cows.

Get the breeder’s opinion

A solid seed stock supplier should be a tremendous resource for you in selecting your next sire. Communicate to them what you want and ask what bulls they recommend. See if the bulls you have identified are ones they believe will meet your goals.

Set a budget and give yourself options

Bull sales can be fast moving events. Know ahead of time what you are willing to spend. Identify your options in terms of bulls you will consider. If the bulls you want quickly blow by your limit, you want to have evaluated if there are others in the offering that still meet your criteria.

Conclusion

Selecting your next herd sires is an important event. Being well prepared can help to ensure that the bull you pick takes your herd genetically the direction that you want to go. An excellent resource that further discusses preparing to purchase your next herd sire is the “Rancher’s Guide to Profit”. This set of videos prepared by the Red Angus Association is available at their website.

Aaron Berger
Nebraska Extension Educator

Using EPDs and Economic Index Values

https://beef.unl.edu/using-epds-and-economic-index-values

February 2015

Expected Progeny Differences (EPDs) have been around for decades and are the best tools available to use in selecting sires with desirable genetic potential as parents.

A recent webinar titled “Genetic Selection Tools in Beef Cattle: EPDs and Antagonisms” outlines how to understand and utilize EPDs in selection.

When selecting sires it is critical to understand potential genetic antagonisms that exist to ensure marketing goals can be met while fitting within environmental constraints. Selecting for increased milk and early growth can be detrimental in some environments and in cases where replacement females are retained and maintenance costs are a concern. Additionally, selection for decreased calving difficulty could potentially lead to replacement heifers that have slightly more difficulty giving birth during their first parity

There are scores of EPDs available and selecting to improve multiple traits simultaneously can be cumbersome – just open up any sale catalog and it is easy to become confused immediately. Economic indexes can help alleviate this confusion. They do so by combining multiple Expected Progeny Differences (EPDs), each weighted by an economic value, into one numeric value often expressed in dollars per animal.

Economic Indexes Defined

An economic index is a collection of EPDs weighted by their economic value such that traits with greater impacts on production goals have a larger economic weight associated with them. The basic equation of an economic index is:

I   EPD1  x  a1  +  EPD2  x  a2  +  EPD3  x  a3…EPDn  x  an

Where: I is the index value; EPDn is the EPD for trait n; and an is the economic weight associated with trait n.

Angus, Hereford, Charolais, Gelbvieh, Limousin, Red Angus, and Simmental all publish at least one economic index.

A recent webinar titled “Genetic Selection Tools in Beef Cattle: Economic Indexes” explains how economic indexes are calculated and provides information on a number of the breed indexes available.

A full description of all available economic indexes can be found in the University of Nebraska NebGuide G1847 Economic Indexes for Beef Sire Selection (PDF version, 374KB) and a full description of all available EPDs can be found in the University of Nebraska NebGuide G1967 EPD Basics and Definitions (PDF version, 704KB).

Matt Spangler, Ph.D.
Associate Professor and Beef Genetics Extension Specialist
University of Nebraska–Lincoln

EPDs and How to Use Them

ARSBC 2018:

Darrh Bullock
University of Kentucky

Crossbreeding should always be a consideration for commercial cattlemen. Crossbreeding has the greatest benefit for reproduction and other lowly heritable breeds.

Practical Guide to Bull Buying
Determine marketing strategy. Will heifers be retained? Make breeding decisions based on specific marketing plan. But, change marketing plan based on current situations.

It’s pretty easy to find a bull that will give you great feeder calves and market animals. When we are keeping replacement females, we are now asking a bull to create females and feeder calves. We’ve given him a new job.

Determine your management level.
What is your labor? How frequently do you visit your cattle? How much attention do you give to them?
What is your level of nutritional management?
Assure that bulls are reproductively sound with a BSE.
Check for structural soundness. This is doubly important if you are retaining females.

The tough one is to set performance levels based on resource availability.

Select for performance using EPDs and indexes.
Determine other factors included horn/polled, color, tempermant, visual attractiveness.

“For trait for which EPDs are available that is the single piece of information you should be looking at,” Bullock said. The other pieces of information including actual measurements, ratios, and genomics feed into the EPDs. Don’t try to outsmart the system!

If you are looking at actual weights and EPDs together, you are reducing your ability to make accurate decisions. Just look at the EPD!

Environment is muddying the water. If we take it out we are improving the tool to make selection decisions.
EPDs is the best tool. Uses all information actual measurements, relatives, environment and genomics. EPDs are a risk management tool, they are not perfect.

One bull has an EPD of 65 lbs. Another has a 50 lbs EPD. The first bull’s calves on average will weigh 15 pounds more.

Prior to EPDs, we basically had no opportunity to select for maternal traits. Maternal traits are predictions on the daughters of the bull.

American Angus Association started publishing EPDs in the early 1980s. Prior to EPDs there was success in increasing growth. Before EPDs you couldn’t select for milk. The rate at which growth was increasing was faster with EPD selection. EPDs allowed us to select for increased growth and decrease birth weight (decreased calving problems).

All breeds have upward pressure for weaning weight. This increased growth is also increasing the mature size of cows. Mature height is under control, it has stayed flat. However, mature weight continues to increase. Mature height does not dictate nutrional requirements. Mature weight is what drives feed needs.

The trait we need to focus on is calving ease, not birth weight. Birth weight is simply an indicator of calving ease.

We need to be careful with selecting for more milk, or we will run into issues like we did with the frame race in the 1980s. Too much milk can lead to reproductive failure.

Most DNA variants (SNPs) have very small effects. But, when we add them all together they can have large effects.

Without a genomic test, accuracies are low. But, if we send in a DNA sample and do the DNA testing, it is the same as having 24 calving ease records out of that bull.

Calving Ease Direct is the tool to look for bulls that have calves that come easy. Calving Ease Maternal tells us if the heifer has the potential to calve unassisted.

Use EPD closest to marketing endpoint (weaning weight, yearling weight, carcass weight). Keep in mind correlated responses in calving ease, milk, and mature weight.

For maternal traits, watch for too much milk. There are Heifer Pregnancy, 30-Month Pregnant, Stayability and Sustained Cow Fertility for selection for reproduction.

Carcass traits are highly heritable and can make a lot of progress in first year of selection.

Selection indexes allows for comparison on a single value. Look for an index that matches what you are trying to do.

EPDs are breed specific. Different breed associations are continuously updating EPDs. Others are still updating on a twice a year basis.

Percentile rankings are one of the most under utilized tool in cattle selection. It is a great tool to find where in a breed a bull ranks.

Summary
Commercial bull buyers should be practicing crossbreeding
Best tools for selection are EPDs and indexes.

Link to video of Bullock’s presentation: https://www.facebook.com/AngusJournal/videos/2146961142208480/
See ARSBC Newsroom for more information. http://www.appliedreprostrategies.com/2018/newsroom.html
Note: this post was live blogged and may contain errors.

EPDs 101: Use Information to Improve Your Herd

Jared E. Decker
Associate Professor, Division of Animal Sciences, University of Missouri
http://blog.steakgenomics.org/2019/03/epds-101-use-information-to-improve.html

Can we be frank for a minute? It is quite simple: EPDs work. When we use EPDs to make selection decisions (which bulls to buy, which females to keep and cull), the performance of our herd improves. Let’s discuss why EPDs work, how they can be used, and pitfalls to avoid.

Defining EPD

EPD stands for Expected Progeny Difference. “Expected” in this context is a loaded word. We use it here the way a statistician would use it. Expected means we are describing a prediction of the future. Expected also means we are discussing an average, not a single observation. What is the average that we are predicting with EPDs? We are predicting the average progeny, or the average of an animal’s calf crop. Finally, when we are discussing EPDs we are discussing differences. Either the difference between two animals or the difference between an animal and the breed average.

The Key to EPDs

What makes EPDs special? Genetic predictions, i.e. EPDs, separate genetic variation from the total variation in a trait. There is a key piece of information that is essential to do this. We need to have some measure of genetic similarity. In the past, we used pedigree information to estimate this genetic similarity. Now we use a combination of DNA data and pedigree data to measure genetic similarity. With measures of genetic similarity, we can separated the bell curve for the variation in the trait into two parts: first, a genetic variation and second, other sources of variation. Now that we have the genetic variation isolated, we can use that informationto make genetic decisions.

Contemporary Groups

Contemporary groups are another important piece of genetic evaluations. Contemporary groups are groups of animals from the same farm or ranch that were managed the same, are the same sex, and are similar in age. By accounting for contemporary groups in genetic evaluations, we remove sources of similarity or differences that are not due to genetics. This makes the genetic evaluation more accurate. By using contemporary groups, we can perform a national genetic evaluation.

The Purpose of a Bull Sale

What is the purpose of a bull sale? What are we buying at a bull sale? What is the purpose of a bull? And, what distinguishes a great bull from a good bull?

We do not go to a bull sale to buy the environment. We do not go to a bull sale to buy management practices or feed rations. When we purchase a bull, we are buying genetics. A bull is simply a delivery mechanism for the genetic potential of our next calf crop. Bulls should be measured on the performance of their calves. The ultimate measure of a bull is not how he looks, but how his calves perform and affect our profitability.

Far too often, bull buyers try to buy management, nutrition and environment when they purchase a bull. While a bull needs to be fertile and sound to do his job, his main purpose is to provide genetics for the next generation. When we make genetic decisions based on actual performance or adjusted performance, we are trying to purchase the management of the bull. Management is not passed on to future generations. Only by using EPDs to make genetic decisions do we focus our decisions on genetic merit. Genetic evaluations take raw measures and create information we can use when purchasing a bull.

How EPDs Are Used

We use EPDs to rank animals from the most favorable to the least favorable. For example, suppose we want to increase the growth potential of our herd. We can rank potential artificial insemination (AI) sires from those with the largest Weaning Weight (WW) EPD to those with the smallest WW EPD. We would then purchase semen on the bulls with the largest WW EPD to increase the weaning weights in our herd. But, we need to discuss two pitfalls with this hypothetical example.

First, we need to avoid single trait selection. We do not want to focus on one trait. By focusing on one trait, we often take one step forward for that trait but two steps back on other economically important traits. Focusing on multiple traits can be difficult, but economic selection indexes make this easier. Economic selection indexes combine multiple traits into a single number based on each trait’s economic importance. Commercial producers should identify an index that matches their production system and marketing endpoint.

Second, extremes are not always better. For some traits, a middle or optimal value is best. We want birth weights that are small enough to avoid calving difficulties. But, we do not want calves born so small that they do not thrive as newborns. We also want Milk or Maternal (MAT) EPDs that match our forage resources. We want cows that provide adequate nutrition to their calves. However, cows with high genetic potential for Milk or MAT have high maintenance energy requirements and cannot fully express their milk production potential. These cows waste forage resources and in some environments may have trouble breeding back. EPDs can be used to select cattle that are at or near breed average; EPDs do not require selection for extremes.

Avoiding Pitfalls

EPDs can be imprecise, e.g. miss the mark, for individual animals. This is especially true if it is a young animal with very little data. There are a couple of strategies to counteract this.

First, we can turn in more data on an animal. Seedstock producers can collect as much data as possible and turn complete, clean data into their breed association. Commercial producers can work with seedstock producers who are passionate about data reporting. An easy way to get more data is made possible through technology. DNA testing a bull to produce genomic-enhanced EPDs is equal to reporting about 20 progeny records for all published traits. Genomic testing improves the accuracy of EPDs as it allows us to better measure the genetic similarity of animals in the genetic evaluation.

However, we should not double- or triple-count information. One of the ways we commonly see people do this is when selecting a calving ease bull. They often look at the actual birth weight, the Birth Weight EPD, and the Calving Ease Direct EPD to make this decision. But, this practice makes these decisions less accurate, because instead of adding information they are adding together uncertainty. Further, the Calving Ease Direct EPD contains the information in Birth Weight EPD and Birth Weight EPD contains the information in the actual birth weight. So, the best practice is to simply look at the Calve Ease Direct EPD that contains all of the available information.

Second, we can hedge our bets. Too often in beef breeding, we are looking for the “One” great bull. But, in reality, the “One” does not exists. Instead of using one bull, we hedge against changing EPDs by using a group of bulls. Because EPDs are unbiased, some of the bulls in the group will have their EPDs go up, others will have their EPDs go down, and others will stay the same as EPDs are updated with more data. The average of this group of bulls will remain the same before and after the EPD updates. However, we are at the mercy of randomness if we use a single bull. His EPDs might stay the same, go up, or go down. Because EPDs are predictions of the average, we can use this property to protect ourselves against uncertainty.

How EPDs Work in Practice

Suppose we have two bulls, Black Bull and Gold Bull. Black Bull has a WW EPD of 2 and Gold Bull has a WW EPD of 22. There is a 20 pound difference in the EPDs of these two bulls. At the same ranch under the same management and environment, we mate each of these bulls to 100 cows apiece. Fifteen months later, we wean the resulting calf crops. The Black Bull’s calves average 495 pounds at weaning, with the majority of the calves weighing between 445 to 545 pounds. The Gold Bull’s calves average 515 pounds at weaning. The 20-pound difference in the EPDs of the bulls is reflected in a 20-pound difference in the average of their calf crop. However, due to the randomness of inheritance and genetics, some of the Gold Bull’s calves under perform the Black Bull’s average and some of the Black Bull’s calves outperform the Gold Bull’s average. We cannot do much to change the shape of the bell curves. However, with the use of EPDs, we can move the bell curve in the direction we want it to go.

Conclusion

Cattle producers can use EPDs to use all the data available boiled down to information they can use. EPDs predict genetic differences and inform selection decisions. EPDs produce the desired results when used consistently and properly. Whether in good times or bad, EPDs help us accomplish our goals.

http://blog.steakgenomics.org/2019/03/epds-101-use-information-to-improve.html

EPDs Work Management Perspectives: No hype

Management Perspectives: No hype: EPDs work
As EPDs and other breeding tools get more complicated, some ranchers have returned to the “tradition” of just looking at animals to determine their genetic worth. DON’T. EPDs work.

Due to objective genetic predictions such as EPDs (expected progeny differences) and indexes, the cattle industry has made tremendous progress in production and efficiency. However, as the models that produce the predictions become more sophisticated and producers understand less of the mathematics behind them, some people are turning off from the technology.

This is a problem because, although calculation of modern genetic predictions have become complicated, the precision and reliability of the EPDs has likewise improved.

An EPD is defined as the difference in expected performance of future progeny of an individual, compared with expected performance at some base point for the population. EPDs are estimated from phenotypic and genomic merit of an individual and all its relatives. They are generally reported in units of measurement for the trait (e.g., lb., cm., etc.). EPDs are best used for comparing the relative genetic transmission differences to progeny between individuals.

What it boils down to is EPDs let a producer sort out genetic differences between animals, eliminating the “noise” of the environment. Some producers think they can do this better with their eyes or just a simple set of scales. This has been soundly proven wrong. The most glaring example of this occurred in Red Angus.

The breed was founded based on performance principles in 1954 with performance reporting as a requirement for registration from the very beginning. Although all Red Angus breeders had weights and measures from the beginning, the breed made no genetic progress for over 20 years. That all changed when it began converting this data into information in the form of EPDs. Since the breed started calculating EPDs, the genetic trend for traits measured has improved linearly.

 
Red Angus also studied the phenotypes for various traits and how they compared to the genetic predictions of the population. An example is weaning weight EPDs, which have been increasing linearly. This lines up perfectly with the breed’s adjusted weaning weights, which have improved at the same rate as the EPDs. EPDs have also allowed the breed to beat genetic antagonisms like increasing weaning weights without increasing birth weight.

Indexes are an even more powerful tool for genetic improvement. Certified Angus Beef studied when cows were flushed to either low or high $B ($Beef terminal index) bulls and all progeny were fed out and harvested. The progeny out of the high $B bulls were significantly better for all input traits into the index including weight per day of age, age at harvest, carcass weight, quality grade, and yield grade. The progeny of the high $B sires had $48.65 lower feedlot production costs and produced carcasses with $166.82 more value for a total financial benefit of $215.47.

The prediction models have also been proven to be unbiased. Cornell University did a retrospective study of the American Simmental Association’s cattle by going back and adding two years of data at a time. They then observed the differences in how cattle’s genetic predictions changed as they went from pedigree estimates through being proven sires. Animals changed up and down as the possible change chart indicated they would, as more information was added to the genetic predictions. They equally moved either up or down demonstrating no bias in the model producing the genetic predictions. If the model was biased, the predictions would tend to move in only one direction.

The basic input into genetic predictions is contemporary group deviations, and the models assume there is no environment by genotype interaction. Cornell also studied this in the Simmental population, and the assumption was validated as true.

That the models have been improving over time only makes the genetic predictions and indexes even that much more valuable.

Genetic predictions using field data were first introduced to the industry with the 1971 Simmental Sire Summary, but those early models were fraught with problems. The early models were based on sires and all dams were assumed to have equal genetic merit, which of course is not correct.

Early models also didn’t account for mating bias. The most common case of mating bias occurs when high-priced artificial insemination sires are only mated to producers’ top cows, so accounting for this bias is important. Over time, these and many more problems have been eliminated. However, with these improvements, the models have become ever more complicated and more of a challenge for the layperson to understand how they work.

This brings us to today’s modern genomic models, which are light years better than the old models, but the complicated statistics that go into the genetic predictions are admittedly hard to understand. The goal of the genetic predictions has always been to sort out what is genetic—thus will be transmitted to progeny—from what is due to environment. Marker-assisted selection is the ultimate way to determine genetic value because, by definition, genomics are not influenced by environment.

Adding genomics to traditional information that goes into genetic predictions—like contemporary group deviations, heritability, and trait correlations—all adds up to predictions that are more precise and reliable. They do a much better job of establishing genetic relationship between animals, as well as identifying markers associated with causative genes, all to improve accuracy of genetic predictions.

The whole goal to animal breeding is to improve cattle genetically. This means different things to different people—some are looking to optimize genetics to their environments while others are looking to maximize the genetic potential for traits.

Whatever a producer’s goal, EPDs and indexes are the best way to achieve it. Today’s prediction models do an unprecedented job of removing all the noise from EPDs and indexes, allowing producers to make the most informed genetic selection decisions possible.

It has been demonstrated time and again that visual evaluation and simple weights and measures are inferior substitutes for modern genetic prediction. Those who ignore objective genetic predictions do so at the long-term peril of their business’ ability to compete.

Performance pioneer Don Vaniman summed it up nicely in 1978 when he wrote, “Is it those who feel cattle that look good must perform, or those who accept that animals that perform look good?” — Dr. Bob Hough, WLJ correspondent

Dr. Bob Hough is the retired executive vice president of the Red Angus Association of America and a freelance writer.

EPDs only one part of the genetic selection formula

EPDs most valuable when used with best practices

Extension / Publications / Bull Buyer’s Guide

Never underestimate the power of your bull. Selecting and purchasing a bull for your beef herd could be considered one of the most important decisions you make in your operation. Don’t make a quick, unprepared decision on purchasing a bull. Never consider purchasing a bull without a proven record and a sound genetic background. Using a bull with poor performance and a weak genetic base could delay improvements in your herd for several years. The small expense you have in purchasing a bull is the difference between the purchase price of the new bull and the salvage value of the old bull (see Example 1). This investment will add efficiency and profitability to your herd for years to come.

Example 1. Cost of a bull purchase

 

$3000 Purchase Price of New Bull
-2090 Salvage Value of Old Bull (1900 lbs. X 1.10/lb.)
$ 910 Net Cost of New Bull

If the new bull sires 90 calves over the next 3-5 years, $910 ÷ 90 = $10.11 cost/ calf. If the bull sires 90 calves that are 10 pounds heavier at weaning and they sell for $1.09/lb. (3-year average for 500-pound calves ? GA Auction Markets, 2009-2011) at weaning, you will have paid for the bull.

The cost of purchasing a bull may seem high at a glance; however, that expense becomes relatively small when it is spread across your bull?s calf crop for a three- to five-year period. Example 1 shows how you can turn an expense into a savings. Bull procurement decisions can greatly impact your future calf crops and herd genetics for many years. When you consider that the bull contributes one-half of the genetic makeup of your calf crop and may sire 25 to 40 or more calves per year, it is easy to see that he is the most important individual in the herd. Keep in mind that a bull that will improve a herd must have genetic superiority over both the cows in the herd and over pervious bulls.

The best way to remain efficient in today’s beef industry is continue to produce more pounds of product per cow exposed. That task can become hard to achieve without the help of a superior bull. Fortunately, weight at various ages is heritable. Birth weight and weaning weight are estimated to be about 30 percent heritable, while yearling weight is about 45 percent heritable. This means that a certain degree of birth weight, weaning weight and yearling weight is inherited from the parents and that progress can be made by selecting for these traits.

Selection Tools

Birth, weaning and yearling weights are normally used to evaluate breeding animals. Actual or adjusted weights may help in making comparisons between bulls in the same contemporary group (a group of animals from the same herd, year and season that is raised together under the same conditions). Since environmental factors like feed and weather affect weights, actual or adjusted weight can be misleading if bulls come from different contemporary groups. Within a herd, weight ratios help account for some of the environmental differences between contemporary groups. But, ratios can also be misleading if bulls come from different herds. Expected Progeny Differences (EPDs), on the other hand, are calculated across herds. A bull’s EPD for a trait is a more accurate estimate of his genetic worth than his weight, adjusted weight or ratio. EPDs not only account for contemporary group and herd differences, they also include information on a bull?s relatives as well as his individual performance. Breed associations report EPDs on weights and many other traits.

Most major breed associations have National Cattle Evaluation programs. Breeders who are involved in their breed’s performance program should have birth, weaning and yearling weight EPDs available on yearling bulls. In all of these breeds, weight EPDs are expressed in pounds of calf. For example, if bull A has a weaning weight EPD of +45 and bull B has a weaning weight EPD of +35, the calves produced by bull A are expected to weigh, on the average, 10 pounds more at weaning than those of bull B, assuming the bulls are bred to comparable cows.

Advances in National Cattle Evaluation have made estimating a bull’s genetic worth more accurate than ever before. EPDs allow valid comparisons of all bulls of the same breed, but they do not allow comparison of bulls from different breeds. Since breeds have different average performance, base years and evaluation procedures, direct comparison of EPDs from different breeds can be extremely misleading. It should also be noted that a bull with an EPD of zero is rarely average. In most breeds, zero is the average of some base group of animals. Since breeds change over time, in some breeds it is possible to find bulls with positive weaning and yearling weight EPDs that are several pounds below the average of all yearling bulls in that breed. Current breed averages and information on how to use EPDs are included in breed association sire summaries, which are available on most major breed association websites.

Accuracy Values (ACC) are usually published with EPDs. The accuracy values indicate the reliability of the EPD, or how likely the EPD is to change as more information becomes available. Accuracies are usually expressed as correlations ranging from zero to one. The closer the accuracy is to one, the more reliable the EPD is. Yearling bulls normally have low accuracy values. Older AI sires can have very high accuracies.

Recommended Performance Standards

Weaning Weight ? Yearling Weight

Commercial producers are paid for pounds of calf. Two very important traits to consider are weaning and yearling weights. However, single trait selection may result in problems with other traits. A good example is selecting for yearling weight alone, which results in increased birth weight because the two traits are genetically correlated. Select bulls that have an excellent combination of performance EPDs that are at or near the bulls’ breed average. Desired genetic improvement involves a combination of several traits, including weaning and yearling weights.

Milk Production

Maternal ability within a breed can best be evaluated with milk EPDs; however, milk is not measured directly in beef cattle performance programs. It is measured in terms of how it affects weaning weight. Milk EPD on a bull is an estimate of pounds of calf at weaning produced by the bull’s daughter due to her milking ability. For example, if bull A has a milk EPD of +5 and bull B has a milk EPD of +2, all other things being equal, bull A’s daughters should produce calves that wean 3 pounds heavier than those from daughters of bull B due to extra milk production. There is some variation in the terminology used by different breed associations in reporting maternal EPDs. An explanation of maternal EPDs is included in a breed’s sire summary.

Producing extra milk requires that a cow consumes extra protein and energy. High milk production can affect a cow’s ability to breed back after calving. For this reason, selecting for maximum milk production is not a good idea in most commercial herds.

Conformation

The cattle industry produces cattle of all breeds, sizes, ages and quality. There is a market for all of them. However, if you sell feeder calves or feed out your own cattle, consider the following points:

  • Good quality cattle eat no more feed than low quality cattle and are just as efficient at converting feed to beef.
  • Bulls should generally have a muscling score of one and be medium plus to large minus framed, according to the USDA feeder calf standards (Table 1). Such calves will bring a higher price than lower grade calves.
  • Low quality cattle with poor conformation usually are more subject to price declines in years of over production than are high quality cattle. Small framed cattle mature early and are slow, inefficient gainers if fed past maturity.

Frame Score

Hip height in inches is used to give an indication of frame size. Most bull test stations and a large percentage of purebred breeders will have a yearling hip height for each animal. Table 1 gives the ranges of hip height as they relate to mature frame size. Remember, taller cattle do not necessarily grow faster or more efficiently, but they do have a later maturity pattern. Small-framed cattle are discounted in Georgia markets. A bull needs to have enough frame to produce calves that are at least USDA Medium.

Table 1. Hip height relative to mature frame size

 

USDA Frame
Small Medium Large
Frame score 1 2 3 4 5 6 7
7-month hip height (in) 36 38 40 42 44 46 48
12-month hip height (in) 41 43 45 47 49 51 53
Potential slaughter weight 800 900 1000 1100 1200 1300 1350+

Birth Weight

First calf heifers have the most calving problems, so buying a bull with a low birth weight EPD is extremely important when the bull is to be used on heifers. Birth weight is the single most important trait that influences calving difficulty. While many cattlemen look at actual birth weights on bulls, birth weight EPDs are the most accurate measure of a bull?s potential calving ease.

Many breeds report Calving Ease EPDs that are calculated using birth weight and calving scores. These can also be helpful in selecting bulls. Refer to the breed association?s sire summary for a description of how these are reported for a particular breed.

Scrotal Circumference

Research indicates that yearling bulls with large testicles sire daughters that show estrus at an earlier age than bulls with smaller testicles. Be sure the bull you select has a scrotal circumference that is at least 30 cm at 1 year of age.

Physical and Semen Evaluation

If the bull you are considering buying is 12 months or older ask for a physical and semen examination. This can be done by the local veterinarian and will increase your confidence that the bull will be able to settle cows.

Other Traits

Breed associations report EPDs for many other traits and this large volume of information can be overwhelming to the bull buyer, so focus on the basics listed above. You do not have to understand every aspect to be able to select a good commercial bull. When you become comfortable with the basics, consult the breed association website for updates on the most recent developments.

How Much “Bull-Power” Do I Need?

Several factors can help determine the number of cows that can be bred to one bull.

Age

The number of cows per bull will vary with the bull’s age, condition and libido. Use an adequate number of bulls with good libidos. Bulls should be in good body condition, but not fat, at the beginning of the breeding season. Young, growing bulls may require extra feed during the breeding season to meet their protein and energy needs. A yearling bull should not be expected to breed more than 20 to 25 cows, while a mature bull with large testicles, good semen and good libido can breed 25 to 40 or more cows.

Condition

You cannot expect fat or thin bulls to perform up to the standards of properly conditioned bulls. Poor nutrition can influence semen quality. Fat bulls lack the stamina to breed enough cows.

Length of Breeding Season

Length of the calving season and number of calves born during each 21 day period of the calving season does have some influence on the number of cows that can be bred to one bull. Mature bulls can breed up to 40 cows during a 60- to 90-day breeding period and sire a high percentage of these calves in the first 40 days of the calving season. If cows are run in large groups, two bulls that are the same age and breed could run with 80 cows.

Breeding Systems

An artificial insemination (AI) program will not require as many bulls, but the quality of the bulls turned out after the AI period needs to be very high to ensure against poorer quality calves than the AI sired calves. Have a short AI program, no longer than 40 days, and then turn out the cleanup bulls.

Other Factors to Consider when Buying a Bull

  • The bull you buy should be functionally sound — a good breeder with a long life ahead — and he should be structurally correct, with sound feet and legs and strong pasterns.
  • The bull should not have swollen joints and should be able to move freely and easily.
  • The bull should not be extremely nervous. A bull with a mean disposition is difficult to handle and he may pass on his nervousness to his offspring.

Be sure you do not buy disease when you buy a bull. Request a copy of the bull’s health record. Place new bulls in an isolation paddock where you can observe them for 30 days before putting them with the herd.

Where to Buy a Bull

Many top cattlemen think where to buy a bull is the most important choice involved in their purchase. You need to know that records of birth dates, rate of gain, weaning weights and health conditions of a bull are just as the seller says. You need to know that the breeder will live up to his responsibilities. It has been said that records and pedigrees are as good or as poor as the integrity of the breeder. Here are some recommendations:

  • Buy from a breeder whose integrity is above reproach.
  • Buy from someone who has complete performance records on his cattle, and knows what those records mean.
  • Buy from a place where you know the type of management under which the bulls were produced.
  • Buy bulls from central test stations where all records are available.
  • Buy bulls from performance oriented producer sales.
  • Buy bulls from breed association sponsored sales.

Using Artificial Insemination

Artificial insemination increases your chances of promoting the important traits. Since many of the bulls in the AI studs have a great number of progeny with performance records, you can predict more accurately what their calves’ performances will be in your herd. AI services also screen their bulls closely for any undesirable traits.

Whether you breed your cows by AI or not is a decision you must make based on your own labor and management situation. However, you can consider AI as one method of “buying a bull.”

Selecting a Bull for Crossbreeding

It is just as important to select bulls for a crossbreeding program based on traits that are heritable as it is for other breeding systems. You can improve your herd by careful selection and produce hybrid vigor at the same time.

Determining a Bull’s Worth

It is very difficult to predict the dollar value of a particular bull; however, the following factors can affect a bull’s value:

  • The number of calves the bull may sire.
  • The performance level of the herd on which the bull is to be used. Almost any good bull will improve the performance of a poor herd, while only very superior bulls can help a high performing herd.
  • The type of breeding system you select. Purebred breeders can usually justify a higher bull investment than can commercial producers.

Summary

Selecting and buying a herd bull is the quickest way to make genetic improvement in your herd. The selection process must include looking for those traits that are economically important and highly heritable. Your own herd records are necessary if you are to select a bull that will improve your genetic base. Demand and buy bulls with total performance that will improve your herd.


Status and Revision History
Published on Jul 01, 1994
In Review on Feb 03, 2009
In Review for Major Revisions on Feb 03, 2009
Unpublished/Removed on Jul 03, 2012
Published with Minor Revisions on Jul 25, 2012
Published with Full Review on Mar 31, 2017

Bull Buyer’s Guide: Beef2Live.com

Are you sifting through stacks of bull sale catalogs looking for your next bull? While bull selection can be a daunting task, your choice will impact your herd for years to come. Thus, taking some time to think about what you need from your next herd sire is important.

Here are some points to emphasize when it comes to bull selection.

Know your market. Understand what traits are value added-traits for your market. One of the best parts about the cattle industry is the different ways producers achieve their goals. While selling calves at weaning into the commodity market is the majority, some cattlemen are marketing in very creative ways. Local freezer beef, retained ownership, alliances, branded beef programs, video sales, or fitting the production environment to a consumer demanded practice are all ways farmers are adding value to their calves. Your bull selection should be based on traits that are profitable in your market.

Don’t sacrifice functional traits or adaptability to your production environment. It is really easy to get caught up in the data, but remember these critters need to be sound and function in the pasture. Good feet and legs, a strong libido, and docility are all imperative. Masculinity, big testicles, and a tight sheath are good phenotypic indicators of the right kind. Buying bulls that are raised in similar conditions to your farm is preferred. You can buy someone else’s genetics, but you can’t buy their management.

Require a passed BSE (Breeding Soundness Exam) and farm herd health protocols. I also suggest a quarantine period for new purchases. A minimum of two weeks will allow time for potential pathagens to break without exposing your herd. Lots of times cattle coming from a sale have experienced elevated stress. It is important to keep them on good feed, in a clean pen, and allow the quarantine period to run its course.

Identify and understand Expected Progeny Differences (EPDs) and phenotypes that signify value added traits you are seeking. Calving ease (CE) is an important and valuable trait. Sometimes when talking to producers I hear them stressing CE and birth weight (BW). BW is an indicator trait for CE, but you don’t get paid for light birth weight calves. You get paid by not having to invest time and labor in pulling calves. So, avoid putting too much downward pressure on BW, especially if the bull will breed cows. Another mistake I see is purchasing low BW bulls for cows. This is not necessary. Many times you can purchase a bull with average or better calving ease for cows at a discount to “heifer bulls” with comparable growth. Smooth, flat shouldered bulls with decent CE EPDs are good value bulls for breeding mature cows.

If you sell your calves at weaning through the salebarn and keep your own replacements, traits of priority should be CE, heifer pregnancy, stayability, and weaning weight. Selecting for more yearling weight, too much milk or too little milk, or cacarss traits are much less important in this scenerio. If you retain-ownership in you cattle through the feedlot and market to the packer, then yearling weight and carcass traits become more relevant to your bottom line. Your ultimate goal should be to produce the most profitable product, thus seek traits that add value without increasing cost of production over the value of the trait.

Utilize appropriate multiple trait selection indexes. Find the sweet spot/ profitable window in milk, YW, and carcass EPDs. Avoid putting too much emphasis on one trait. Nearly all breeds now have dollar index values that help put economics to trait selection. These can be extremely effective tools if the index scenario matches your operation. Weaned Calf Value ($W) is a dollar value used by the Angus breed. It is an index that is designed for cattlemen that primarily sell calves at weaning. This index also assumes that replacement heifers are retained. EPDs for birth weight, weaning weight, milk, and mature cow size are focused on. Lower birth weights, heavier weaning weights, and lower mature cow size are desirable. Milk production is weighted both positively and negatively as it directly impacts calf weaning weights, but also increases cow maintenance requirements. A more detailed description of economic selection indexes is available on my blog

Don’t be fooled by index names. Beef Value ($B) is a terminal index. It is a great tool for cattlemen that are not keeping replacements. This index will increase profitability of cattle in the feedlot and on the grid. Unfortunately, I have heard $B referred to as a comprehensive EPD several times which it is not. It is vital to understand that $B is a terminal index. Don’t be afraid to ask questions. The breeder or an Extension specialist will be able to help explain the numbers.

Demand higher accuracy for traits. Technologies are available for seedstock producers to increase the accuracy of EPDs on yearling bulls. Genomic-enhanced EPDs result in less risk, less change, and more predictability in how a yearling bull will sire. A bull buyer can feel more confident now than ever in EPDs when they are backed by genomic testing.

Heterosis. Crossbreeding systems are hard to deploy and maintain in small herds. However, leaving hybrid vigor on the table in a commercial herd is a big loss. Otherwise lowly heritable traits like reproduction, health, and cow longevity are best improved by crossbreeding. Crossbred cows and maternal heterosis is a key to profitability on commercial cow/calf operations. Studies have shown net profit per cow is increased by $75/cow/year as a result of maternal heterosis.

Buy the right size, type, and demand quality. I would compare this to buying a car or truck. If you have little money for gas (feed), then don’t buy a gas (feed) guzzler. Buy a bull that fits your cow herd. Your cows will tell you the right size and milk production for your management. If they come up open… they are not the right size. Now, you also want a bull that is the right type. You don’t buy a fancy sports car for a work vehicle do you? So why buy a fancy, sexy bull to produce working kind cattle? To me there is a difference in fancy and quality. I suggest you demand quality. Select a product that will last and hold value. Look for signs that the breeder stands behind their product. That is a good sign of quality.

Seek value when buying a bull. The lowest priced bull is seldom the best valued. If you find a bull that has the traits you are looking for… buy him. Set a budget, but understand it is often hard to find everything you are looking for. Bulls with the traits you are seeking can add value to your cattle in a hurry. They can add far more value than a cow. The bull you buy this year will impact your herd for the next 5 years with his calves, but his daughters will impact your herd for the next 20 years. Make a good investment. Buy a bull that adds value to your calves and your cowherd.

Written by Travis Meteer, Extension Educator, Commercial Ag, University of Illinois, and used with permission.

Find the Right BULL