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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.

Bull Selection: New Calculator To Determine The Value Of A Bull

Editor’s note: The following is part four of a four-part series that helps you to evaluate different breeding programs, which bulls are optimal for your herd, and how much they’re worth. (See part onepart two and part three).


Different traits of bulls can contribute to different impacts on the bottom line of the operation. For example, a bull with a higher calving ease EPD may contribute to more live calves. Not surprisingly, bulls with higher calving ease (or lower birth weights) sell for a higher price (Simms et al., 1997). With the large variation in bulls available, bull prices extend over a wide range from $3,000 to over $20,000 per head.

Identifying a fair price during sire selection contributes to higher efficiency in operation economics. To estimate breakeven bull price, a bull valuation calculator has been developed. The purpose is to provide a general idea of how much a bull is worth based on key farm parameters.

Bull Values – two Scenarios

The value a bull provides depends on his individual performance, the environment (ex: pasture productivity), management (cow:bull ratio) and markets (calf price). For example, large framed bulls require more feed, leading to a higher maintenance cost, but that may be offset by heavier calves at sale time.

Two scenarios were studied – a low maintenance farm versus a high maintenance farm. Table 1 shows the parameters entered for each farm. The default values in the calculator are the averages of the two scenarios.

The low maintenance farm is assumed to have a larger pasture size reducing the cow to bull ratio, multiple bulls in a field with potential for fighting as well as rough terrain contributing to reduced bull longevity, and reduced feeding costs over fewer days, resulting in lower maintenance costs. This management style is reflected in the cow herd as well with a lower weaning rate and lower weaning weights.

The high maintenance farm is assumed to have smaller breeding pastures, more labour, and more feed, which leads to a higher cow to bull ratio, greater longevity, higher weaning rates, and higher weaning weights.

Despite keeping key parameters constant like the proportion of the calf value attributed to the bull and expected calf price, there is a large variation in bull value between the two farm scenarios (Table 2).

The high maintenance farm has a breakeven bull price more than double that of the low maintenance farm. In fact, the low maintenance farm would have had a much lower breakeven price if the annual maintenance cost was similar to the high maintenance farm. However, the lower annual maintenance cost helped to offset the lower cow to bull ratio and lower weaning rate.

For the high maintenance farm, the producer can afford to pay more for a bull given the expected performance of both the bull and its offspring. The large variation in bull prices on the market reflects the different abilities of the bull to bring value to an operation. This is impacted not only by the bull but also the environment and management system used by differing operations.

Driving Factors of Bull Price

The value a bull provides is in the calves sired over a lifetime, the long-term genetic change of the herd, and salvage value at the end of a productive life. (As long-term genetic change is not readily measurable by producers, this parameter was excluded from the calculator.)

The value provided depends on:

  • cost factors (i.e., bull maintenance cost and death loss),
  • performance factors (i.e., years of service, the expected cow to bull ratio, expected weaning rate, expected weight of feeders, and proportion of the calf value attributed to the bull), and
  • price factors (i.e., expected price of feeders and salvage value).

 

 

 

 

**Download the Excel calculator here**

Note: this calculator is currently available in Excel only. A web option will be developed in the near future. 

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EPDs only one part of the genetic selection formula

EPDs most valuable when used with best practices

Burke Teichert’s top 5 tips on bull selection

Burke Teichert | Oct 06, 2016

Last month I talked about culling the right cow.You should cull cows to keep your herd cleaned up and managerially efficient. This minimizes the time required for doctoring, calving problems, taking care of the wild ones and the labor requirement for a strung out calving season. It also reduces the number of animals that are hard to market. In the process, you will also have a positive effect on herd fertility, health and adaptation to your management and environment.

Bull selection can result in rapid change. However, change may not always result in progress or improvement. In fact, I will suggest that a lot of our so-called “improvement” in cattle growth rates has been more than offset by reductions in stocking rates, conception rates and herd health.

The result has been more time spent doctoring cattle, lower conception rates and/or higher feed bills, and fewer pounds produced per acre. Because the calves that are produced are bigger, they bring less per pound. Therefore, we now sell fewer pounds per acre at a lower price per pound.

We are now seeing research on this. In only one case have I seen calf weaning weights higher as cow size decreases. Usually calf weights decrease as cow size decreases, but not proportionally.  So, when stocking rates are adjusted to fit cow size, enough more cows can be run that, in spite of lighter calves, more pounds are weaned per acre.

On many ranches, the number one determinant of profit is the ratio of grazed feed to fed feed.  Once you have gotten over doing a lot of feeding, stocking rate becomes the number one determinant of profit; and stocking rate is determined by cow size and milking ability along with grazing and pasture management. Next comes herd fertility. Then, in a group, come marketing, cows per person ratio and herd health problems.

Therefore, let’s take all of that into consideration as we make bull selections. Here are five tips:

  1.  Cull the right cow: Why would I want to buy a bull born to a cow that I would have culled at my ranch? Go through your cull criteria and ask if the mother of “that” bull would still be in your herd. I firmly believe that, if you have reduced feeding to the bare minimum, have selected good, moderate-sized bulls and have culled cows as I described last month, you have some very good cows. Those are the kind of cows that should be mothers of bulls.
  2.  Size and milking ability: If you want cows that can graze most of the year and get pregnant early in the breeding season, and if you want to wean more pounds per acre by running more smaller cows with less milking ability, you will want to select bulls with less mature size and lower milk EPDs.

    I’m sure there is room for some difference of opinion here, but to maximize pounds produced per acre and at the same time keep supplemental feed cost at a minimum, I want cows to be as small as they can be and still produce a feeder calf that will be acceptable at the market place.

    I know the feeder and packer seem to want them bigger and bigger. But you need to stay in business first. There is information indicating that producers are using bulls with higher and higher EPDs for milk and for weaning and yearling weight. But actual weaning weights on the ranches have not changed in recent years. However, cow size has.

    If your attempts to produce bigger and bigger calves are robbing you of conception rate and good herd health, are costing you more in feed cost and supplementation and reducing your stocking rate, you should reconsider your breeding priorities.

  3.  Heterosis: Carcass traits are quite highly heritable. Growth traits are moderately heritable. Milk is less heritable and fertility, health and longevity are considered to be the least heritable.

    But, because carcass traits are highly heritable, they don’t respond much to heterosis while other traits do. The rest of the traits respond, with the more highly heritable having a smaller response and the less heritable having a greater response to heterosis. Optimum heterosis is most likely different for each situation, but I want a significant level of heterosis in every cow.

    Heterosis will significantly enhance fertility and health while slightly increasing milk and growth. You can’t expect selection to do what heterosis does nor vice versa.Parenthetically, I think that some aspects of fertility—first cycle conception as a yearling and calving interval—are more highly heritable than heritability estimates would suggest.

  4. Disposition: As an industry, we have made great progress across many breeds on disposition. I think every bull should be carefully scrutinized for disposition. It is refreshing and encouraging to see herds of cows in breeds with reputations of poor disposition that have wonderful dispositions.

  5.  Growth and carcass: Improving growth rates and carcass traits is desirable as long as the negative consequences don’t overbalance the positives. When you make sure that the bulls you purchase will produce the kinds of cows you want, you then need to move carefully and cautiously to get the desired results without undoing much of the good you have accomplished.

    I think it can be done, but carefully and slowly. Genomics and heterosis, if they can become compatible, could help move growth and carcass forward faster without undoing progress in the other traits. Currently, a number of genomic tests only validate in high percentage Angus cattle. When those tests are valid across a number of breeds and crosses, much progress could be made.

Perhaps the best breeding decision a commercial producer will ever make is the choice of a seedstock provider. Find someone whose breeding objectives mirror your own, who operates in an environment similar to yours, who can help you benefit from heterosis and can understand your objectives and help you select the right bull.

P.S.—I continue to maintain that about 40% of the cows in America should be bred to terminal-cross bulls. Producers choosing that option should buy cows (not heifers) from producers who cull cows and select bulls as I have described. They should then select bulls with high growth and carcass EPDs for use on those cows—not the moderate EPDs that I have suggested in this article for those producing replacements.

 

Burke Teichert, a consultant on strategic planning for ranches, retired in 2010 as vice president and general manager of AgReserves, Inc. He resides in Orem, Utah. Contact him at burketei@comcast.net.

Cow’s Mothering Rating

Cow’s Mothering Rating

Posted July 28th, 2018 — Filed in Stockmanship

I have been following a thread on another e-mail list comparing the mothering rating of the cow that tries to attack anyone who gets close to their new-born calf as opposed to the cow that is OK with this. The consensus seems to be that the mellow cow is not as good mother as the cow that will try to eat you. I disagree with this.

Bud and I found that when you work livestock properly – that is, by using pressure/release methods instead of force and fear, the cows learn to respect but not fear you.  Since they don’t feel you are a threat to them, they also don’t think you are a threat to their calf so they don’t “get on the fight” when you need to handle their new baby.

When we lived in Canada we were involved with a Beef Booster cow herd.  In case you aren’t familiar, this is a composite breed.  Some of the herds were rated “Maternal.” Their main function was to produce heifers to go into the cow herd, another raised “Terminal bulls” to use on the herds that would market all of their calves, etc.  The man we worked for had about 100 head of cows that were designed to raise “Terminal bulls.”  He wanted to change over to a “Maternal” herd so he swapped his herd with a neighbor.  When these cows were delivered the neighbor also delivered a list of ear-tag numbers of cows that would kill you if you tried to handle their baby calf.   The only way they could weigh and tag the calf was with a bucket loader on a tractor.  A man in the bucket would get the calf, then the tractor operator would try to raise the bucket before the cow could climb in, too.  We received these cows in October.  We handled them quite a lot.  If the feedlot shipped a pen of cattle and there was still feed in the bunks, we’d put these cows in the pen for a while to let them clean the bunk.  Through the winter we tried to move their straw bed every few days to make it easier when they farmed the ground in the spring.  This usually meant we had to drive the cows to the new bed a couple of times to discourage them from going back to the old one, etc.  When spring came the owner was able to weigh and tag every calf with no aggression from any of the cows.

The first year we worked on the elk ranch In Texas, we didn’t see an elk calf until it was a couple of weeks old.  The following year, the cow elk would bring their newborn calves with them when we drove through the pasture, scattering hay.  We even had one calf born in the corral.

Meeting Your Goals

Selecting Bulls to Meet Your Goals –

By Kit Pharo

I came across an internet article late last week entitled, “Selecting Bulls to Meet Your Goals,” or something like that.   It wasn’t worth the time it took to open the link – but it did get me to thinking.   I suspect most cow-calf producers have no goals.   They are just doing what everyone else is doing and/or what they have always done.   If you don’t have goals, you have no direction in your life or business.

Do you have business goals?   I’m not talking about ideas or dreams you think about every now and then.   I’m talking about real goals.   If you have real goals, you are probably one in a thousand.   If you have real goals, you have a HUGEcompetitive advantage over everyone else in your business.   If you have real goals, you are creating your own future.   If you have real goals, you are also creating a future for the next generation.

A real goal must be Specific, Measurable, Attainable and Time-Sensitive.

  1. Specific: Goals are no place to waffle.   This is no place to be vague.   Vague goals produce vague results.
  2. Measurable: Always set goals that are measurable.   If they are not measurable, you will never know for sure when they have been achieved.   For example, don’t set a goal to “make more money.”
  3. Attainable: Goals must be realistic and attainable.   Most people don’t set goals – so when they do, they tend to set goals that are too big to be easily attained.   This creates discouraging results.
  4. Time-Sensitive: Every goal should have a timeframe attached to it.   A goal must have a deadline – a time in which you want to accomplish it.

I have achieved the best results when I break my big goals down into several (or many) smaller goals that can be easily attained in a relatively short period of time.   I liken my really big goals to an elephant that must be eaten.   There is no way I can eat an elephant in one sitting.   However, I will eventually eat the entire elephant – one bite at a time.

If you do not have any business goals, I encourage you to set some.   Start out by just setting one simple goal that should be easy to attain.   Do it today!   Someday is not a day of the week.   I cannot think of anything that will even come close to giving you a greater return on the time invested.   You will literally amaze yourself!

Let’s go back to the subject of bull selection…

Since the bulls you purchase are responsible for at least 90% of your herd improvement (or deterioration), it makes sense that bull selection can play an extremely important part in helping you meet your goals.   Are you purchasing bulls that will help you achieve your business goals?   Are you purchasing bulls that will increase your future success and happiness?   Are you purchasing bulls with the next generation in mind?

Quote Worth Re-Quoting –

“Setting goals is the first step in turning the invisible into the visible.”   ~ Tony Robbins

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 Selection Breeding Programs That Suit Operational Goals

Editor’s note: The following is part one of a four-part series that will help you to evaluate different breeding programs, which bulls are optimal for your herd, and how much they’re worth.

There are a range of different beef operations in Canada, and there is no one breeding program that is optimal for all operations. Breeding programs will be determined by operational goals and the management practices that fit those goals.

Here are some examples.

A producer that sells weaned calves at auction may choose a crossbreed program with high calving ease and a focus on performance gained from hybrid vigour; or they may prefer the uniformity of a purebred program with reputation premiums.

A producer that retains heifers and is looking for maternal replacements may be focused on maximizing the performance through inbreeding and outcrossing within a single breed; or they may develop FI crosses with higher reproductive performance and longevity.

These choices may be limited by the number of breeding fields available or the number a producer is willing to manage. There are a variety of breeding programs available, and effective sire selection requires an understanding of the characteristics of the available genetics as well as your own operation.

Each breed of cattle has distinct traits that allow them to excel in different geographical or management environments (Table 1). Depending on the goals of the operation, a sire can be chosen that has the potential to make positive changes for your operation in the areas you’ve identified for improvement.

Table 1. Comparison between beef cattle breeds in Canada (Adapted from Agriculture Victoria, 2017)

Indicators:
• E: Early, A: Average, L: Late
• S: Small, M: Medium, L: Large
• 1 = high/desirable; 5 = low/undesirable

Source: http://agriculture.vic.gov.au/agriculture/livestock/beef/breeds/breeds-of-beef-cattle

Also see Beef Improvement Federation’s across breed EPDs

Purebred

The advantage of the purebred or straight-bred approach of using only one breed is a homogeneous herd where cattle responses to environmental and nutritional factors are easier to predict. There will be consistency in nutritional needs, weaning, yearling, or finishing weights, and days on feed. The largest advantage is the ability to market a relatively uniform product, but ease of planning, and providing breeding stock forcommercial operations intending to maximize hybrid vigour may also be considerations.

When the parents have very similar genetics, the calf is more likely to have two sets of identical genes (homozygosity), which can have beneficial effects if the genes are associated with superior performance. However, negative traits can also show up with homozygosity. This can lead to the expression of abnormal traits, such as lethal recessives (e.g. curly calf syndrome, dwarfism, neuropathic hydrocephalus, etc.) It can also have more subtle effects on overall performance by increasing the amount “inbreeding depression” in the population.

Inbreeding depression is a reduction in performance due to the mating of highly related individuals, and it most negatively affects reproductive traits, followed by growth traits, but seems to have little effect on carcass traits. It is associated with an increased percent of open cows and stillbirths, with decreased levels of survival, growth, and overall performance (Northcutt et al). Generally, caution must be exercised when inbreeding as there is a high risk of performance reduction if the breeding program is not managed very carefully.

Three common purposes of inbreeding are to:

  • to test a bull for the presence of undesirable genetics that show up with inbreeding
  • develop inbred lines for a crossbreeding system
  • linebreed, or to maintain the genetic contribution of a genetically superior individual in the larger population

Linebreeding seeks to preserve and continually improve upon the genetics of a high performing ancestor. While linebreeding mates closely related individuals, it seeks to minimize the level of homozygosity (and thus inbreeding depression) while maintaining a high level of relationship to the high performing ancestor. Linebreeding is typically merited when there is difficulty finding outside bulls with sufficient performance to improve the herd.

Key components of a successful linebreeding program include:

  • individuals selected for a linebreeding program must be of superior quality with no genetic defects
  • meticulous record keeping of breeding history, parentage records, and animal performance
  • aggressive culling at signs of defects or lower performance – the starting herd should be as large as possible to accommodate aggressive culling
  • keeping inbreeding levels low

To keep inbreeding levels low, the recommendation is to keep the genetic contribution of the same ancestor to 50% or less (van der Westhuizen, 2016). To illustrate, the progeny of mating a daughter to her sire will have 75% of genetics from the sire. Generally, matings that involve full siblings and parents to offspring are discouraged. Instead, matings of uncle/niece, half siblings, and first cousins are potential strategies.

Outcrossing, or the breeding to non-relatives or distant relatives (i.e., at least 4 generations away) within a breed, is the most widely used mating strategy in purebred herds. Outcrossing can be used to increase performance levels, avoid inbreeding depression, and restore performance lost to inbreeding depression (Evans and McPeake). The more genetically dissimilar the animals, the larger the potential benefit. One drawback of this system is that, if the outcrossed progeny were to be mated, it is more difficult to predict the phenotype of the calves due to the variation in genetic background.

Crossbreeding

With crossbreeding, cattle from different breeds are mated. As the genetics from both parents can be very different, both the positive and negative effects seen in outcrossing are magnified with crossbreeding. Crossbred herds are much more unpredictable in terms of calf weight, maturity time, and nutritional demands. However, there are two key advantages:

  • Heterosis or Hybrid vigor – this is the opposite of the performance reducing effects of inbreeding depression. Heterosis provides improvements, especially in the area of reproduction and growth. The effect of hybrid vigor is dependent on the animal having two different copies of a gene, where the more unrelated the breeds, the larger the potential improvements.
  • Breed complementarity – where the strengths of two different breeds are combined. For example, when mating Charolais bulls to Hereford-Angus crossbred cows, the Charolais bull contributes growth and performance genetics, while the Hereford-Angus cows have desirable maternal and carcass quality attributes. This may not be seen in every individual animal, but is observed in herd averages.

Studies (Gaines et al., 1966; Turner et al., 1968) have found that compared to purebred, crossbred cows have a 10% increase in calf crop and calves weaned, with the calving percentage of the crossbred cows being consistently higher than their parents. Gregory et al. (1978) found crossbred cattle to be 7 kg heavier and 9 days younger at puberty than their purebred counterparts.

Crossbreeding improves reproductive performance, longevity, and maternal ability of the cow. This is manifested through increased calf survival rate, as well as increased weaning weight. Overall, the performance improvements from crossbreeding can have significant impacts on the bottom line of beef producers.

There are many crossbreeding strategies, for example:

  • 2 or 3 breed rotation,
  • terminal cross,
  • bull rotation, or
  • composite breeds.

A terminal cross is where both parents are purebreds of different breeds, and the resulting calves are a 50:50 mix. However, to maintain this specific breed ratio, replacement breeding stock from purebred herds must be used instead of rebreeding the offspring.

Another strategy is mixed breeds, where multiple breeds are used without maintaining specific ratios of each breed in the progeny. While this strategy does not require complex breeding management, there is lower uniformity and a higher level of uncertainty regarding calf performance.

The optimal strategy will depend on the operation itself; for example, if calves are sold at a pre-sort sale or are part of a large group and able to fill an entire feedlot pen, uniformity becomes less important.

For further reading on crossbreeding, NBCEC (2010) introduces an overview of different strategies and Gosey (1991) presents a more in-depth discussion.

There are also challenges and considerations associated with a crossbreeding system (NBCEC, 2010):

  • a small herd (i.e., less than 50 cows) can limit choice in crossbreeding strategies
  • a higher requirement for breeding pastures and bull breeds for the more complex crossbreeding strategies (e.g., rotational systems)
  • more record keeping and cow identification as the current breed composition of cows can affect sire and heifer replacement selection
  • less uniformity in progeny
  • no crossbreeding system can overcome low quality bulls

There is no one-size-fits-all solution or breeding program that is best for all scenarios, as the right genetics depend on the individual operation. Key determining factors include: the management style of the operation, heifer retention (i.e., terminal versus maternal sires), number of breeding fields, and time of marketing. For example, a farm that auctions their calves at weaning may choose a mixed breed program with high calving ease, while a farm that direct markets their beef may prefer the uniformity of a purebred program.

There are many different types of bulls available, and effective sire selection requires an understanding of the characteristics of the available genetics as well as your own operation. Deliberate alignment of the bull’s genetics to your operational goals will contribute to enhanced revenue and reduced costs.

Editor’s note: Stay tuned for part two in this four-part series.

Bull purchases should be a planned event

Robert Wells for Progressive Cattleman Published on 24 January 2019

Prescribed fire is a common practice to help control brush in native grass pastures. Those who implement prescribed fire will spend numerous hours and dollars preparing for this practice before it is implemented.

A prescribed fire will have an impact on the ranch for three to five years.

In contrast, a bull purchase decision will have an impact on the ranch for as long as his genetics are represented in the herd. If replacements from a particular sire are kept, his influence will outlive him on the ranch. It amazes me that most producers do not put as much thought and effort into sire selection as they will a prescribed fire.

The influence of a sire will have just as much or more of an impact on the ranch economics for years.

Selection decisions

Numerous decisions and processes should occur before writing the check for a new bull. Start early in order to give yourself enough time to work through the process. First, a producer needs to define his or her ranch goals and how the new bull will help to meet those goals. It is difficult for a bull to excel in every trait, and the few that do are too costly for the average commercial cattleman to buy and use for natural service.

Will the bull be used as a terminal or maternal sire? Once the decision is made on how the bull will be used, the producer should pick the breed to use and find the bull within the breed that meets their goals.

After the bull breed has been decided upon, it is time to do the early “homework” before you go to the seller’s ranch. Identify the reputable breeders in your region from whom you might purchase a bull. Request sale catalogs or registration numbers, date of birth and EPDs (expected progeny differences).

The easiest method I have found to handle the large amount of data you will sort through is to develop a spreadsheet with all the data from each bull. This allows you the ability to sort data numerous ways and easily filter out those bulls that do not meet your criteria.

Go to the breed website and look up the percentile rank tables for nonparent bulls. By doing so, you will be able to determine the relative quality of the bull for each trait. This gives you perspective as to how good and bad a bull is for each EPD trait.

I call this process “judging class on paper.” Consider the actual weights, but do not let them solely dictate your final decision. EPDs are more reliable than individual values as management can have a dramatic impact on birth, weaning and yearling weights; marbling scores; and backfat measurements.

Once you arrive on-site, you will now have a short list of bulls to phenotypically consider. Finally, a realistic price should be set on the value of the bulls you will consider. Base your purchase price on how the EPDs of interest will increase your profit potential for that bull. Some traits, like performance traits, are easier to determine the value, such as weaning or yearling weight.

Here is an example of how to place an economic value to a bull. Angus bull A has a weaning weight EPD of 67 (10th percentile). The breed weaning weight average is 52 (50th percentile). Bull A should sire calves that will be 15 pounds heavier than the average Angus bull. This bull will sire 125 calves over five years (bred to 25 cows for five years). Multiply the additional 15 pounds by 125 calves.

The result is an additional 1,875 pounds of weaning weight. If a modest value of gain of $1.35 per pound is used, the additional lifetime weaning weight from the better sire is worth $2,531.

Now, you can add this number to the average price for bulls in your area to determine the maximum bid price for this bull. If the average bull value is $2,250 plus $2,531, the breakeven for this bull would be $4,781. Assuming calves are sold at weaning in this scenario, anything less than $4,781 for the purchase price will be the profit potential of the bull.

The same calculations can be performed for all performance, carcass traits or index traits. This calculation does not take into account the intrinsic additional value you may receive for a better-perceived quality calf, such as selling a No. 1 versus a No. 2 quality calf.

Physical evaluation

Now that the homework is done, it is time to go to the bull sale and evaluate the bulls physically. Only consider the bulls on your short list. Do not deviate from the hard work you have done before sale day. The best bull on paper may be a structural nightmare and should not be bought.

Be extremely critical, and do not allow for deformities or structurally incorrect bulls. When physically judging the bull, start at the hooves and legs, then work your way up to the rest of the body. The bull should have good angles at the fetlock, hocks, shoulder and hip. A bull that has structurally incorrect legs (post-legged, sickle-hocked, etc.) will not last long in the herd.

Move the bull around and make him walk out to ensure he has a smooth, long stride and is not lame. Evaluate him from all sides – front, back and the side. This part is especially difficult with video auctions since most sale videos are short and only provide the side perspective. I once had an order buyer tell me he looks for calves that have “lots of butt and lots of guts.” Find the bull that has the most body capacity and is balanced.

Think of a rectangle. You want the body to be balanced, and as long, deep and wide as possible. You want a bull that will sire this type of calf. Likewise, disposition should be evaluated to ensure the bull will be amicable when you handle him.

Purchase day

Finally, the buyer should consider or beware of certain things when at the sale location. Make sure to pick up any supplemental sale sheets as lot numbers or data associated with a given bull may have changed. Sale day announcements will take precedence over any written information in the catalog.

Confirm the lot number of the bull in the ring before you start bidding, as a lot number may be skipped. Listen closely to the bidding process, as it will move very quickly. If you are not a seasoned bidder, sit close enough to the ring man that he can tell you where the bid price is at – do not hesitate to ask for confirmation.

In addition, for the inexperienced buyer, let another person set the opening bid. Determine the bid increment the auctioneer is using; typically, it will be in increments of $250 or $500. Try to get in on the bidding so you will be able to have the last bid at your maximum price. It is never a good feeling for a bull to sell to someone else at your maximum bid price, as you will wonder if you could have bid that value, would you have been able to get the bull bought.

Additionally, find out if the bull has passed a breeding soundness exam prior to the sale and any other health tests, such as a negative test status for Johne’s disease or persistent infection of bovine viral diarrhea virus (PI-BVDV).

Finally, know what guarantee comes with the bull. Will the seller honor the bull through the first breeding season or first year; if so, for what conditions? Most breed associations define a sound breeding bull as the bull only has to settle one cow in six months’ time. Is this the definition the seller will use, or does he have his own breeding guarantee terms?

Much planning and preparation should go into the purchase of a new bull. When possible, make a planned decision as to when the bull exits your program, and start the search early for his replacement. If you have a spring-breeding herd, when possible, look for his replacement in the fall. This will give you many opportunities to find the right bull at the right price.

Remember, the last bull in the sale is not the last bull for sale in the region. Do not lock yourself into a must-buy situation from any one seller. Doing so will only lead to a costly mistake. Prior planning will result in quality performance of the bull, and you will not be the person who is making a purchase decision “on the fly” while the bull is in the sale ring.  end mark

PHOTO: When observing a bull, try to envision a rectangle. You want the body to be balanced, and as long, deep and wide as possible. You want a bull that will sire this type of calf. Photo courtesy of Noble Research Institute.

Robert Wells

Producers struggle to regulate cow size

Teresa Clark
for The Fence Post

Determining what size of cow is ideal for the environment is a hot topic. It depends on the environment, the ranch, and sometimes the rancher. What is even harder is settling on a certain size of cow, and maintaining it.

University of Wyoming Extension Rangeland Specialist Derek Scasta shared a story about his grandfather’s struggles to maintain cow size in his own herd. “What we have is a lot of information to go through,” Scasta told producers during the recent Southeast Wyoming Beef Production convention. “When my grandfather would go to a bull sale, he was looking for EPDs for low birth weight and higher weaning weight, but he may have ignored the maternal traits, and then kept the higher end of the heifer calves for replacements,” he said. The result over time was larger cows.

Looking at the bull’s maternal EPDs will indicate how the heifer calves will look, Scasta said. The bull may have had a positive EPD for milk and mature size, producing larger daughters. “That is why you really need to sort through the bull catalog and look at those EPDs,” he said.

400 POUNDS

In 1975, the average beef cow in the U.S. weighed 1,000 pounds, which became the range management standard for calculating animal unit months. However, recent data suggests the average beef cow now weighs 1,400 pounds. “In 2010, 16 percent of the U.S. beef cows were more than 1,500 pounds,” Scasta said. “That’s millions of beef cows that weigh more than 1,500 pounds on range and pasture in the U.S.”

Despite a more than 400 pound increase in cow size in the last 40 years, Scasta said no evidence exists to suggest that increase has resulted in weaning larger calves. “We have enhanced the production and performance potential of cows, but we may not be realizing that in terms of calf weaning weight,” he said.

The EPD for yearling weight has increased 100 pounds in the Angus breed, which basically shows ranchers have been selecting for growth in cattle. In 1985, the average carcass weight was 725 pounds, and in 2015, it was 892 pounds, which is 165 pounds larger. “Cattle are basically 20 percent heavier than 35 years ago, and 10 percent heavier than 15 years ago,” he said.

With that amount of growth has come some negatives in relation to animal welfare. Cattle pots were originally designed to haul smaller cattle. “With these bigger cattle, a lot of them will bump their back going into that lower deck, which leaves a bruise on their back leading to a cut out. It is costing the industry $35 million a year because the cattle are bigger today than what the trailers were originally designed for,” Scasta said.

RANGE IMPACT

It is not just a matter of muscle growth. Ranchers have also selected for milk production. “As we have enhanced the performance of our cattle, what has been happening to rangeland? Actually, rangeland has stayed pretty flat despite the production potential of cattle increasing. We have managed to optimize what we get from the range, and it has stayed pretty consistent over time,” he said. “Ranchers have done a good job of matching their cattle genetics with range productivity.”

Scasta said there is a lot of disagreement over optimum cow size. Some studies suggest smaller cows are better because of live weight production and income, while others find larger cows to be more efficient because they have a larger rumen which could be an advantage for the efficiency of processing low quality forages.

A lot of the data available comes from feeding trials, where they did a lot of modeling, Scasta said. “What I found was a lot of mixed studies, and a lack of information in Wyoming,” he said.

Do larger cows wean larger calves?

One study he shared that was published in the Journal of Animal Science, studied how cow size impacts calf weaning weights relative to precipitation extremes. The four-year study involved 80 cows grazing rangeland northwest of Laramie.

The study showed that during the driest years, the larger cows had an advantage, and the smaller cows weaned lighter calves. However, the results were opposite during wet years, and variable during average years. “Taking the average of all four years into account, they found no significant difference in terms of cow size class,” Scasta said. “Smaller cows weaned calves statistically similar to those weaned from the bigger cows, riding the roller coaster of wet-dry-wet-dry,” he said. Calculating the input-output ratio, which is the pounds of grass consumed relative to the pounds of calf weaned, the smaller cows were weaning similar size calves across all wet-dry cycles, Scasta said, while eating less because their nutritional requirements were lower.

A 1,000 pound cow consumed 7½ pounds of grass per pound of weaned calf, according to the study. For a 1,200 pound cow that number jumped to 8½ pounds, and for 1,400 pound cow, it was 9½ pounds. “Basically, the larger cows had to eat more per pound of calf weaned,” he said. “Most ranchers have an efficiency target for the cow weaning a calf that is at least 50 percent of the cow’s body weight. So, a 1,000 pound cow should wean at least a 500 pound calf. In this study, the smaller cows were the only ones to reach that target,” Scasta said.

In another study, Scasta worked with a Wyoming ranch to analyze 8,000 cow/calf records with 13 years of data to determine which cow size is most efficient. The cow size on this ranch varied from 800 to 1,600 pounds, but the majority of the cows weighed 1,100 to 1,300 pounds, Scasta said.

From this data, Scasta found that the smaller to moderate size cows were closer to hitting the 50 percent cow size to weaning weight target, compared to their larger counterparts. “The 1,600 pound cows were actually pretty inefficient for the amount of grass they eat,” he said. “I think the data indicates managing for moderate size cows, and to not let them get bigger over time.” ❖

— Clark is a freelance livestock journalist from western Nebraska. She can be reached by email at tclarklivenews@gmail.com.

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