What Does Ww Mean in Beef Terms
The beef seedstock business is big, and commercial beef producers have many opportunities to purchase bulls that run into the criteria established in their convenance plans. Breed selection and blazon vary considerably, and this diversity helps keep a strong genetic base in the beef concern. Current bull buyer selection tools include visual traits evaluated by the buyer, as well as operation and genetic information.
Availability: Spider web but
To help producers ameliorate understand modern bull-option opportunities, nosotros will reference the iii largest genetic databases: Angus Genetics Inc., a subsidiary of the American Angus Association; International Genetic Solutions, a subsidiary of the Simmental and Red Angus Associations; and American Hereford Clan. Although cattle are bachelor in many breeds, these databases include Angus, Hereford, Gelbvieh, Red Angus and Simmental, and concepts from them can be applied easily to other breeds.
Defining EPDs
Expected progeny differences (EPDs) take been available for more than than 30 years, and the awarding of EPD technology for the genetic improvement of commercial beef cattle tin be a fundamental component of meeting current and future beef product demands. This awarding requires that beef producers institute clear goals for their performance.
Producers as well need a critical evaluation of recent dogie crops, calving events and subsequent dogie production to identify production areas impacted by the option of convenance bulls and areas for comeback. In addition, producers need to consider feed resource, environmental conditions (terrain, boilerplate moisture, etc.) and labor availability to ensure they are selecting the appropriate genetics for their operation.
Producers selling all calves at weaning may prioritize EPDs differently than producers wishing to retain heifers, who may take different priorities than producers wishing to retain ownership through the feedlot. The following is meant to be a brusque guide to help producers employ EPDs accordingly for the selection of breeding bulls that meet their goals.
Expected progeny differences are predictions of the genetic transmitting ability of a parent to its offspring and are used every bit selection tools. For a given trait, data submitted by producers to brood associations from an animal's actual performance, performance of progeny, functioning of other relatives and genomic data (Deoxyribonucleic acid analysis), if bachelor, are all used to calculate EPD values.
Expected progeny differences are numerical predictions based on bodily measurements and genomic information for the various traits on the animal or grouping of related animals. These predictions are refined to provide the best prediction possible to help guide sire selection and are presented in the aforementioned units of the trait being measured.
Weight traits are published in pounds, whereas measurement traits such equally top, depth, width or scrotal circumference are published as inches (English) or centimeters (metric). Traits that involve subjective scores or values are reported in the same units equally were evaluated.
EPD Accurateness
Accuracy (ACC) reflects the precision of a prediction for a given beast'south EPD and provides us with a level of confidence for that brute'due south genetic merit. As more data becomes available for a particular animal, the ACC of an EPD increases. As accuracy approaches 1, the EPDs are more reliable and will alter little with additional progeny. Bulls with greater accurateness values may be called "proven sires."
The EPD prediction of genetic merit for a trait is the best indicator of expected performance of hereafter progeny, which is expressed as deviation from the population'southward base value. Recognizing that base of operations values may exist different amongst breeds is important; some breeds use an boilerplate within a specific yr, whereas other breeds apply a nonspecific historical point.
To better the accuracy of EPDs for younger bulls, producers may collect and submit DNA samples, which, depending on the trait, typically equates to about x progeny records for a sire with no other progeny records contributing to his EPDs. As more progeny data are obtained for a sire, the relative contribution of genomic information to overall EPD accuracy is reduced.
How to Use EPDs
Regardless of which EPDs producers apply in balderdash pick, the basic process of utilizing all EPDs is the same. If one wants to compare 2 bulls of the same brood, decrease the EPD values of ane bull from the other and look at the divergence.
The calculations are a simple mathematical equation: Bull A has a weaning weight EPD of plus 52 and bull B has a weaning weight EPD of plus 36, so the calves from bull A should average 16 pounds heavier at weaning than those calves sired by bull B (52 – 36 = sixteen).
Other traits are the aforementioned. If bull A has a yearling weight EPD of plus 99 and balderdash B has a yearling weight EPD of plus 79, and so bull A's calves should boilerplate 20 pounds heavier at yearling age than bull B'due south yearlings (99 – 79 = 20). If a producer chooses to check these numbers by weighing the calves, the results for a given bull may not exist exact, but through fourth dimension, the genetic tendency will express the desired selection and the calves volition perform as expected.
Which EPDs to Utilise
A mutual question producers enquire is: "Which EPD values should I use?" The answer depends on the goals and current production condition of the producer's herd.
For example, producers who sell the entire calf ingather at weaning or following a backgrounding phase could use a fairly simple approach to EPDs. The EPDs to emphasize in this scenario stand for the direct impact a bull can have on progeny up to the point of weaning or yearling sale. The post-obit are example EPDs from various breed associations that a producer could employ in sire selection:
- BW = birth weight – This is the expected difference in nascence weight of a balderdash's progeny expressed as pounds of calf. The greater the number, the heavier the calf will be at nascence.
- CE or CED = calving ease or calving ease direct – This is the expected difference in percentage of unassisted births from a bull when mated to 2-year-old heifers, with a higher value indicating greater calving ease in first-calf heifers.
- WW = weaning weight – This is the expected divergence in adapted weaning weights of a balderdash's progeny in pounds. The greater the number, the heavier the calves would be at weaning.
- YW = yearling weight – This is the expected deviation in adjusted yearling weights of a bull'due south progeny in pounds. The greater the number, the heavier the calves would be as yearlings.
When producers retain replacement heifers, the following EPDs could be used and added to the previous listing. The previous EPDs are nevertheless of import in this scenario, simply the following EPDs provide additional insight into milk production, mature moo-cow characteristics and fertility of futurity offspring:
- CETM, CEM or MCE = calving ease full maternal, calving ease maternal or maternal calving ease – This is the expected deviation in the percentage of unassisted births of that balderdash'southward daughters, with a higher value indicating greater calving ease in starting time-dogie daughters.
- Milk or MM = milk or maternal milk – This is the expected difference in the amount of preweaning body weight gained by calves that can exist attributed to the milking ability of a bull'southward daughters. It's expressed in pounds of calf. The greater the number, the more than pounds per calf that are added due to milk production of that balderdash's girl.
- TM, MWW, K&One thousand = total maternal, maternal weaning weight or maternal milk and growth – Each of these terms measures a sire's ability to transmit milk production and growth rate to weaning through his daughters. It is the expected difference in the weaning weight of the sire'due south daughters' calves, in pounds, calculated as the milk EPD plus half of the WW EPD of that balderdash.
- MW, MCW = mature weight or mature cow weight – These are a predictor of the difference in mature weight of daughters of a sire, expressed in pounds. The greater the number, the heavier you tin expect the progeny to be at maturity.
- ME = maintenance energy - This indicates differences in mature cow maintenance energy requirements. It is expressed in megacalories per month, with greater numbers indicating that more than feed inputs would be required to maintain torso condition in progeny.
- HP, HPG = heifer pregnancy – This is the expected difference in the probability of female progeny for a bull conceiving as two-twelvemonth-olds. Greater numbers are desired if the goal is to take daughters from a balderdash with a greater probability of being pregnant and calving as 2-year-old heifers.
- STAY = stayability – This represents differences in the percentage of the probability of a bull'south daughters staying productive past the age of six. The greater the number, the longer you could expect female person progeny of a bull to remain in the herd.
- MH = mature height – This is a predictor of the difference in mature height of a sire's daughters, expressed in inches. The greater the number, the taller/larger framed the progeny volition become.
- SC or SCR = scrotal circumference – This is the expected difference in adapted yearling scrotal circumferences of a balderdash'south progeny, in centimeters.
For producers who retain ownership through the feedlot, several additional EPDs will help with choice. In addition, producers selling calves at weaning or yearling age may benefit indirectly from selecting for carcass traits by creating a reputation of raising high-value calves that are profitable for feedlot owners. Those carcass traits are:
- CW, HCW = carcass weight or hot carcass weight – This is the expected difference in adjusted carcass weights of a sire'due south progeny, expressed in pounds. The greater the number, the more pounds of carcass weight.
- Fat, BF = fat or dorsum fat – This is the expected difference in adjusted fat thickness at the 12th rib of a sire'south progeny, expressed in inches. Lower numbers betoken leaner carcasses. Greater number indicates a greater fleshing ability of progeny, compared with a lower number.
- MB, MRB, MARB = marbling – This is the expected difference in adapted marbling score of a sire's progeny, expressed in percentage. A greater number indicates a greater potential quality grade.
- YG = yield grade – It is expressed as the expected departure in the divergence of yield form units for a bull's progeny. A lower number would move progeny, on average, toward lower numerical yield grades than the population boilerplate. Yield Grade 1 equates to more red meat yield, and Yield Grade v equates to less red meat yield.
- SHR = shear forcefulness – This is the expected divergence in pounds of force required to shear a steak from a balderdash's progeny. Lower values bespeak less force to cut through a steak, and, therefore, more tender meat.
- REA or RE = rib-heart area – This is the expected difference in adjusted rib-heart surface area of a sire's progeny, measured in foursquare inches. Selecting for larger REA EPD will emphasize heavier muscled progeny.
Pick Indices
Some breed associations also offering pick indices designed to match common production goals. Typically, a selection index is formed for a set of traits that take product importance in the manufacture. Once an index is identified as needed, extensive inquiry investigates individual traits that should be included, drove of those operation records and analysis to decide economic weights for each of the traits involved.
These economical weights create an equation in which EPDs or raw performance records of those traits are used to create a specific pick index. In the cattle manufacture, these more often than not are reported as dollar values to betoken the amount of profit or savings the producer could look when utilizing that index.
Comparing ii bulls using a choice alphabetize or selection indices is very similar to using EPD comparisons, but it allows a producer to evaluate a unmarried number that combines several traits to meet a focused goal.
Note that indices are listed with specific goals in mind and oft are meant for specific breed or type of crossing; some are for producers selling calves at weaning or retaining buying through the feedlot phase, and others are holistic in nature for producers with long-term herd goals that manage cattle from conception to harvest. To demonstrate the variety of indices available, hither are several examples from selected breeds:
American Angus Association
Weaned Dogie Value ($Westward), an index value expressed in dollars per head, is the expected average divergence in future progeny performance for preweaning merit. $W includes revenue and toll adjustments associated with differences in birth weight, weaning straight growth, maternal milk and mature moo-cow size.
Beef Value ($B), an index value expressed in dollars per caput, is the expected average divergence in hereafter progeny operation for postweaning and carcass value, compared with progeny of other sires.
American Red Angus Association
HerdBuilder Index (HB) is an index using Red Angus bulls mated to cows and heifers, with replacement heifers retained from within the herd and all remaining progeny sold on a quality-based carcass filigree. By using the HerdBuilder Index, producers tin increase the sustainability of the cowherd and, ultimately, their performance.
GridMaster Index (GM) is an index built using the Red Angus bulls mated to cows and all progeny sold on a quality-based carcass grid. The GridMaster Index is for producers whose chief goal is to maximize profitability of feeders in the feedyard and on the rail.
American Simmental Association
All-Purpose Index (API) is an index that evaluates sires for apply on the entire cow herd (bred to Angus first-dogie heifers and mature cows), with the portion of their daughters required to maintain herd size retained and the remaining heifers and steers put on feed and sold on form and yield.
Last Index (TI) is an index that evaluates sires for use on mature Angus cows, with all offspring put on feed and sold on class and yield.
American Hereford Association
Baldy Maternal Index (BMI$) is an index to maximize profit for commercial cow-dogie producers who use Hereford bulls in rotational crossbreeding programs on Angus-based cows. Retained buying of calves through the feedlot phase of product is maintained and the cattle are to exist marketed on a certified Hereford beef (CHB) pricing filigree.
Certified Hereford Beef Index (CHB$) is a terminal sire index in which Hereford bulls are used on British-cantankerous cows and all offspring are sold as fed cattle on a CHB pricing filigree. This alphabetize places no emphasis on milk or fertility because all cattle volition exist final. This index promotes growth and carcass.
American Gelbvieh Association
$Cow ($Cow) is an index of value expressed in dollars for a replacement female relative to other animals in the herd. $Moo-cow includes stayability, reproductive efficiency, milk, calving ease, moderate mature weight, dogie gain feedlot feed efficiency and carcass value.
Feeder Profit Index (FPI) is an economic option index designed to aid producers in selecting sires whose progeny will perform in the feedlot and are sold on grade and yield. Well-ranking sires for FPI have higher marbling and carcass weight than their contemporaries.
Across-breed EPD Comparisons
Realizing that each breed may have a different base of operations value for each EPD and the advisable mode to employ absolute EPD values is inside breed, the US MARC (Meat Animal Research Heart) publishes Across Breed EPD (AB-EPD) tables once yearly. The tables provide adjustment factors for each breed to create a common EPD calibration for bulls of unlike breeds. To view the current adjustments, visit this site and review briefing proceedings to see the electric current twelvemonth's across-breed EPD tables and further instructions for comparing bulls of different breeds.
Many more than aspects of utilizing EPDs are bachelor on the diverse websites for brood associations. This discussion was not intended to encompass all breeds, all traits or the many other tools available through the brood associations.
Knowing breed averages, percentile rankings and other data associated with the breed tin can help producers empathize how private bulls rank in comparison with boilerplate bulls in the breed. Gaining cognition well-nigh EPDs and other associated data is disquisitional to expand a producer'due south understanding of the genetic potential of bull offerings and to make an informed bull buyer'south bid.
The performance of cattle results from a combination of genetics and the environment. Poor ecology conditions or management decisions quickly can reverse any gains made through pick of high-quality genetics.
EPDs are a tools that you tin can use to select bulls to fit your performance. Kickoff with a clear vision of what your goals are for a dogie crop and the future of your cow herd, then find bulls with the visual advent and EPDs to lucifer your production goals.
Examples of using EPDs for bull choice:
Example i. A producer is looking for a Charolais bull to breed to mature black baldy cows that all have had at least 2 calves. This is a last cross, with all calves being sold at weaning or afterwards a backgrounding period. The producer wishes to maintain calving ease and have the benefit of enhanced weight at the fourth dimension of auction.
Which bull would you choose based on EPD values?
Considering that these bulls are almost probable young and accept low accuracies, we would select Bull B. To address the specific goals of the producer:
i) Maintain calving ease
In terms of straight calving ease (CE), which relates straight to the bull's pressure on nascency weight, Bull B is expected, on average, to take ane.v percent fewer unassisted births when bred to two-year-old heifers than Bull A (a disadvantage if convenance to heifers). Balderdash B also has an expected birth weight that would be heavier, on average, than Bull A.
However, here are ii things to consider: Call up that mature baldy females will be used, and we anticipate much less calving difficulty, compared with heifers. In addition, both of the bulls are ameliorate than the brood boilerplate (BA) for both traits. Therefore, the groovy majority of accent in selecting between these two bulls would be put on WW EPD solitary.
2) Enhance sale weight of calves
Balderdash B would be expected to produce calves that are 23 pounds heavier at weaning, on average, compared with Bull A. Considering weight ofttimes drives sales and profits, this is a large difference and important to consider. Furthermore, considering this is a terminal cross, no heifers will exist retained, so maternal calving ease can be ignored.
Case 2. A producer is looking for a Simmental bull to brood to his crossbred, Simmental-influenced herd. Cows and heifers are managed as one grouping during the convenance flavour. The producer is looking to expand his herd through heifer retentiveness and hopes the bull selected will produce females that calve easily and have the longevity to grow old in the herd.
Which bull would you choose based on EPD values?
In this scenario, emphasis would exist put on maternal calving ease, nativity weight and, due to management, direct calving ease for heifer retention. Get-go, if the producer wants to produce females that calve easily, so the bulls' maternal calving ease should be compared. Balderdash A is the preferred bull in this scenario considering he is expected, on average, to take 7.four per centum more than unassisted births in his daughters as 2-year-one-time heifers, compared with Bull B's daughters.
Because that bulls in this scenario too will be used on cows and heifers, the direct calving ease EPD also should be considered. Balderdash A still is preferred in comparing with Balderdash B because the expectation, on average, is that Balderdash A will have 17 percent more than unassisted births in ii-yr-erstwhile heifers, compared with Bull B, and, as well, have calves that are ten.vii pounds lighter at nascency, only adding to calving ease ability.
The selection of Balderdash A is supported further past the stability EPD considering the expectation is that, on boilerplate, an additional 10.9 percent of this bull's daughters volition stay in the herd past age half dozen, compared with Balderdash B'due south daughters, profoundly benefiting the producer's longevity goals.
One note: Because steers would be produced and almost likely sold, Bull A does not have every bit heavy calves as Bull B at weaning, but his daughters' calves (full maternal) will be shut or equivalent to Bull B's daughters' calves due to the expected milking power and associated growth (milk EPD).
Because of this, pick for maternal attributes should non exist detrimental to growing ability for those calves that will exist sold out of the performance. All the same, this producer should be enlightened that heavy-milking cows will require higher feed input.
Example 3. A producer is looking for an Angus balderdash to breed her straight-bred Angus herd. The producer retains ownership through a finishing phase in which cattle are placed on loftier-concentrate diets. The goal is to develop calves that provide the greatest
carcass value.
Which bull would you choose based on EPD values?
To accost the producer's goal as stated, we can await solely at the dollar beefiness value alphabetize ($B) because it provides an indication of expected profit based on growth and carcass characteristics. The $B value, however, shows that the two bulls are extremely similar (just $0.03 difference).
With similar $B values, the price likely would drive the conclusion between the two bulls. If closely priced, this scenario highlights a time when goals need to be more conspicuously defined to pick the bull that is appropriate for the operation. Specific contributions to greater carcass value (CW, MARB, etc.) demand to be identified, prioritized and sought out in potential convenance bulls.
Bull A is expected, on average, to have lighter birthweight calves, compared with Bull B, but those calves are expected to outperform Bull B's calves at weaning and yearling weight (for example, consider their WW and YW EPDs). If the base cow herd is strong in marbling and rib-center area traits, and so perhaps the lighter birthweight and additional growth offered by Bull A make him the better candidate.
On the other hand, Balderdash B has slightly more desirable EPDs for rib-center area and marbling than Bull A. If the base of operations cow herd is strong in calving and growth characteristics, then Balderdash B probable would be the better candidate.
Producers besides should consider specific questions regarding whether heifers volition be retained in the herd and the relative value the producer wants to put on slightly divergent maternal traits offered by the respective bulls. At the cease of the day, maybe the most important factor in ownership bulls is appropriately understanding the performance and the functioning's goals.
Source: https://www.ag.ndsu.edu/publications/livestock/understanding-expected-progeny-differences-for-genetic-improvement-in-commercial-beef-herds
0 Response to "What Does Ww Mean in Beef Terms"
إرسال تعليق