What Does Mw Stand for in Beef Terms

Expected progeny differences (EPDs) have been applied to improve the genetics of beef cattle for almost four decades. Expected progeny differences are predictions of the genetic transmitting ability of a parent to its offspring and are used to make selection decisions for traits desired in the herd. For a given trait, EPD values are calculated based on data submitted by producers to breed associations from an beast'due south actual functioning, functioning of progeny, performance of other relatives, and genomic data (Deoxyribonucleic acid assay, if available).

When DNA information is available, EPD accuracy is improved, and these calculations are referred to every bit a Genomic-enhanced EPD (GE-EPD). Thus, in addition to pedigree, performance and progeny data, GE-EPDs utilize genomic test for increased reliability of an creature's EPD (Eenennaam and Drake, 2012; Rolf et al., 2014).

Source: American Angus Association

Combined with all bachelor sources of information, GE-EPDs are the best estimate of an animal's genetic value as a parent. Genomics permit improve accuracies for younger animals and allows a clear pic of genetic traits of interest, especially those that are expensive to measure such as feed efficiency, carcass traits in convenance stock, reproductive traits or maternal traits in bulls.

When a producer buys a young balderdash that has GE-EPDs, he is ownership with the aforementioned level of confidence in that beast as one that has already sired between ten and 36 calves, depending on the trait. In this mode, GE-EPDs increase accuracy in those animals much earlier in their lives. With all these benefits, keep in heed that genomically-enhancing the EPDs does not change how the EPD tin can be used, it but increases its accuracy.

Table 1. Progeny Equivalents (PE) – Carcass trait PE equate to bodily carcass harvest information, not ultrasound browse equivalents.

Trait	PE
Calving Ease Direct	26
Birth Weight	23
Weaning Weight	27
Yearling Weight	23
Dry Affair Intake	12
Yearling Tiptop	17
Scrotal Circumference	15
Docility	12
Claw Angle	10
Foot Angle	10
Heifer Pregnancy	17
Calving Ease Maternal	20
Milk	36
Mature Weight	15
Mature Height	9
Carcass Weight	15
Carcass Marbling	11
Carcass Ribeye	17
Carcass Fat	14

Source: American Angus Association (world wide web.angus.org).

EPD Accurateness

Accuracy (ACC) reflects the precision of a prediction for a given animate being's EPD and provides us with a level of conviction for that animal's genetic merit. Bulls with greater accuracy values may be called "proven sires."

The EPD prediction of genetic merit for a trait is the best indicator of expected performance of future progeny, which is expressed as departure from the population's base value. Recognizing that base of operations values may be different among breeds is important; some breeds use an average within a specific year, whereas other breeds apply a nonspecific historical point.

To improve the accuracy of EPDs for younger bulls, producers may collect and submit DNA samples, which, depending on the trait, may equates to near 10 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 data to overall EPD accurateness is reduced.

The lack of confidence associated with EPDs on young cattle comes from not having progeny or performance information, both of which increase the accuracy of the EPD. In young bulls, for example, most of their genetic value is based on their pedigree. As these animals age and have offspring, we know more than and more well-nigh their genetic merit. This increased confidence is denoted past an increase in the accurateness value (0–1 scale) associated with each EPD. It does not necessarily mean that the EPD increases if accuracy increases. It just means the EPD becomes closer to the truthful value, whether information technology increases or decreases. Remember that EPD stands for expected progeny difference. Genotyping a young animal increases accurateness because SNP genotypes accept similar value to evaluating additional progeny.

How to Use EPDs

Before getting started with EPDs, producers should ascertain their specific production goals commencement and and then select based on the EPDs that will all-time allow them to meet those product goals. For example, producers selling calves at weaning may prioritize EPDs differently than producers wishing to retain heifers or producers wishing to retain ownership through the feedlot. Therefore, producers should utilise EPDs based on the selection of convenance bulls that meet their personal production goals.

Hither are some traits that tin be used by those producers who sell the entire calf crop at weaning or following a backgrounding stage:

• Birth Weight (BW);
• Calving Ease (CE) or Calving Ease Direct (CED);
• Weaning Weight (WW);
• Yearling Weight (YW).

Selecting for these traits adds ease to the beef producers daily workload, by attempting to reduce the number of assisted births, while adding sale value (with weight) to those calves that will be sold as feeders.

For producers who retain replacement heifers, the post-obit EPDs are often used in add-on to the previous list:

• Calving Ease Full Maternal (CETM), Calving Ease Maternal (CEM) or Maternal Calving Ease (MCE);
• Milk Production (Milk) or Maternal Milk (MM);
• Total Maternal (TM), Maternal Weaning Weight (MWW) or Maternal Milk and Growth (M&Thousand);
• Mature Weight (MW) or Mature Cow Weight (MCW);
• Maintenance Free energy (ME);
• Heifer Pregnancy (HP or HPG);
• Stayability (STAY);
• Mature Elevation (MH);
• Scrotal Circumference (SC or SCR).

These traits are all related to the predicting the success of replacement heifers at condign valuable dams in the herd.

Producers who enhance their own animals through the feedlot will frequently focus on the traits below, in addition to the maternal traits previously mentioned:

• Carcass Weight (CW) or Hot Carcass Weight (HCW);
• Fat (Fat) or Back Fat (BF);
• Marbling (MB, MRB or MARB)
• Yield Grade (YG);
• Shear Strength (SHR);
• Rib-Eye Area (REA or RE).

In this instance, the traits selected are value traits for cattle marketed at the finish of life.

Example 1 of Using EPDs for Balderdash Choice

In this example, a producer is looking for a Charolais bull to utilise on blackness Angus-influenced cows that have had at least ii calves. In this example, the producer is using the Charolais in what is chosen a terminal cantankerous, all calves being sold at weaning or after a backgrounding period for slaughter. The producer wishes to maintain calving ease and accept the do good of enhanced weight at the time of sale. Based on the table below, which balderdash would be more appropriate for the stated purpose based on EPD values?

Table ane. Charolais bulls¹ for use on mature crossbred females.

Balderdash	CE	BW	WW	YW	MCE	MILK	SCR	CW	REA	Fat	MARB
A	11.6	-4	27	58	3.ix	23	1.1	xx	0.66	0.041	0.18
B	2.9	3	59	99	two.ii	1	2.ane	49	0.96	0.041	0.22
Breed Average	3.1	0.7	24.iv	43.viii	four	seven.9	0.6	fourteen.7	0.26	0.002	0.04

ⁱBulls information retrieved from Select Sires Beef and Genex.

With the focus on this phase of product, accent should be given mainly to 3 traits: CE, BW, and WW. We are assuming that these bulls are most probable young and accept low accuracies, or are not proven.

Calving ease (CE) relates directly to the balderdash's pressure on birth weight. Bull B is expected, on average, to have 8.7 pct fewer unassisted births when bred to two-year-quondam heifers than Bull A (a disadvantage if breeding to heifers). Bull B has an expected birth weight that would exist 7 pounds heavier, on average, than Bull A. Thus, while clear that Bull A would be more appropriate for breeding heifers, our producer is interested in breeding multiparous cows. Therefore, because bull B has a BW EPD that is only 2.three lb. heavier than the breed average, the producer likely will want to put their accent on other traits. Exam of the WW EPD indicated that Bull B would exist expected to produce calves that are 32 pounds heavier at weaning, on average, than Balderdash A. This divergence is what normally drives sales and profits at weaning. Thus, if the producer decides to sell calves at weaning fourth dimension, Bull B may be the appropriate pick. In addition, while peradventure non every bit important if the producer sells at weaning, this producer may also desire to look at YW and some carcass traits when selecting their bulls. In this case the logic is that selling high quality calves at weaning that will perform well effectually yearling historic period and through the feedlot may create a reputation of raising high-value calves that are profitable for feedlot owners. Considering this is a terminal cross, no heifers volition be retained, and maternal traits can be ignored.

Option by Index

Now, in improver to individual trait option using EPDs, animals tin can also be selected on an "alphabetize". An economic index is a tool used to select for several traits at in one case based on a specific breeding objective. An economic index approach considers genetic and economic values as well every bit the relationships betwixt traits to select for profit. When genetic improvement is desired for several traits that may differ in variability, heritability, economic importance, and in the correlation amongst their phenotypes and genotypes, simultaneous multiple-trait index selection has been more effective than contained alternative levels or sequential selection (Philipsson et al., 1994; Garrick and Golden, 2009).

These are some examples of the economic indices offered by breed associations. Each breed association has many more selection indices and producers are encouraged to investigate these options.

From the American Angus Association (AAA, 2020):

• Beefiness Value ($B), an index value expressed in dollars per caput, is the expected boilerplate difference in hereafter progeny performance for postweaning and carcass value.
• Combined Value ($C), expressed in dollars per caput, is an alphabetize which includes all traits that make upward both Maternal Weaned Calf Value ($Thou) and Beefiness Value ($B) with the objective that commercial producers will replace 20% of their breeding females per year with replacement heifers retained inside their ain herd.

From the American Hereford Association (AHA, 2020):

• Baldy Maternal Index (BMI$) is an index to maximize turn a profit for commercial cow-dogie producers who use Hereford bulls in rotational crossbreeding programs on Angus-based cows.
• Certified Hereford Beef Index (CHB$) is a terminal sire index in which Hereford bulls are used on British-cross cows and all offspring are sold as fed cattle on a CHB pricing grid.

From the American Simmental Association (2020):

• All-Purpose Index (API) is an index that evaluates sires for utilize on the entire cow herd (bred to Angus kickoff-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 grade and yield.
• Concluding Alphabetize (TI) is an index that evaluates sires for use on mature Angus cows, with all offspring put on feed and sold on grade and yield.

Example 2 of Using EPDs for Bull Selection

A producer is looking for an Angus balderdash to breed a direct-bred Angus herd. The producer plans to retain ownership of the females to use in the convenance herd and sell the calves at weaning. Thus, maternal traits of the females will be important.

Tabular array two. Angus bulls^ane for utilise on straight-bred Angus females.

Bull	CED	BW	WW	YW	CW	Marb	RE	Fat	$M	$W	$F	$Thousand	$B
A	16	-0.6	68	129	62	1.8	i.11	-0.028	62	79	124	120	244
B	xvi	-2.5	64	118	32	0.42	0.53	0.046	51	78	69	38	106
Breed Average2	3	1	26	45	22	0.42	0.32	0.008	52	54	82	44	126

¹Bulls information retrieved from Select Sires Beef.
²Breed average retrieved from The American Angus Association.

To accost the producer's goal as stated, nosotros can look at the Maternal Weaned Calf Value ($M) because it provides an indication of expected maternal ability and profit based on sale of weaned calves. Balderdash A will produce calves that volition profit, on boilerplate, $eleven more than Balderdash B using the $Grand. Balderdash A volition be the better buy for this scenario where female memory and weaned dogie value are both important.

Across-breed EPD Comparisons

Within a brood, EPDs can be directly compared. Bulls of different breeds can also be compared, but adjustment factors to the EPDs are needed because an EPD from i breed evaluation is non straight comparable to an EPD from some other breed evaluation. Since 1993, the U.S. Meat Animal Research Center (USMARC) has produced a table of these adjustment factors and then that the merit of individuals can be compared across breeds.

Example three of Using EPDs for Bull Selection

In this example, suppose a producer needs to make a determination between a Simmental balderdash and a Limousin balderdash to breed his crossbred cow herd. The important traits for him are BW, WW, YW, and Milk.

Table 3. DEPs from dissimilar breeds to utilize on a commercial crossbred herd.

Bull	CE	BW	WW	YW	Milk	Dr.	YG	CW	REA	Marb
Simmentalone	17.1	-3.9	68	95.7	26.three	7.four	-0.22	28.2	0.58	0.35
Limousin1	14	1.vii	61	90	21	8	-0.73	sixteen	one.23	viii

¹Bulls data retrieved from Select Sires Beef.

With the above data, the producer also needs to access the table beneath:

Table iv. Adjustment Factors to Estimate across-breed EPDs.

Breed	Birth Wt. (lb)	Weaning WT. (lb)	Yearling Wt. (lb)	Maternal Milk (lb)	Marbling Scorea	Ribeye Area (in2)	Fat Thickness (in)	Carcass Wt. (lb)
Angus	0.0	0.0	0.0	0.0	0.00	0.00	0.000	0.0
Hereford	ane.4	-16.5	-44.4	-12.v	-0.30	0.02	-0.073	-71.1
Red Angus	two.half dozen	-nineteen.four	-31.4	i.5	-0.03	0.25	-0.040	-13.2
Shorthorn	four.5	-34.four	-46.6	-0.1	-0.07	0.47	-0.032	5.6
South Devon	2.6	-29.9	-55.4	3.i	-0.53	0.64	-0.213	-68.8
Beefmaster	iv.0	23.4	one.one	7.7
Brahman	10.iii	53.3	14.four	16.7		0.03	-0.166	-35.9
Brangus	3.1	14.9	v.3	12.9
Santa Gertrudis	five.2	xl.iv	39.8	xvi.eight	-0.44	0.12	-0.085	-12.three
Braunvieh	2.ii	-21.1	-46.6	iv.1	-0.61	1.00	-0.100	-53.four
Charolais	half-dozen.six	32.7	23.2	8.one	-0.29	0.79	-0.201	v.1
Chiangu	2.8	-21.1	-36.2	two.5	-0.47	0.59	-0.142	-19.3
Gelbvieh	2.9	-15.5	-27.ane	8.2	-0.37	0.66	-0.066	one.five
Limousin	2.5	-sixteen.ix	-53.9	-ii.iv	-0.03	0.59	-0.024	-five.one
Maine-Anjou	2.four	-30.3	-55.2	-7.0	-0.43	0.95	-0.179	-35.1
Salers	0.9	-xi.2	-48.0	5.6	0.07	ane.08	-0.177	-47.6
Simmental	ii.viii	-xi.six	-19.2	1.8	-0.12	0.45	-0.049	-7.v
Tarentaise	2.7	20.2	-12.ane	15.7

^aMarbling score units: 4.00 = s1°0; 5.00 = Sm00
Source: U.s.a. Meat Animal Inquiry Center (2020) through Beef Improvement Federation.

With both tables of information, a table for across breed comparisons can be made, like to Table 5.

Tabular array five. Example of using beyond-breed aligning factors to convert noncomparable within-breed EPDs to comparable across-breed EPDs.

Bull		BW (lb)	WW (lb)	YW (lb)	Milk (lb)
Simmental	EPD1	-3.9	68	95.7	26.three
	AB Adj. Factors2	2.8	-11.half dozen	19.2	one.8
	AB-EPDthree	-ane.1	56.iv	76.5	28.one
Limousin	EPDane	i.vii	61	ninety	21
	AB Adj. Factors2	two.5	-sixteen.9	-53.9	-2.4
	AB-EPD3	four.2	44.1	36.1	18.6

ⁱEPDs are the inside-breed EPD values from the brood'southward genetic evaluation for the bull of involvement.
^twoAB adj. factors are the across-brood adjustment factors from Table 1.
³Beyond-breed EPDs later adjustment factors are applied to within-brood EPDs.

The beyond-brood (AB) adjustment factors for BW are 2.8 lb for Simmental sires and 2.5 lb for Limousin sires. The AB-EPD for that trait is -3.9 lb + 2.8 lb = -1.1 lb for the Simmental bull and 1.vii lb + 2.5 lb = 4.ii lb for the Limousin bull. The expected nascency weight difference of offspring when both are mated to cows of another breed (e.grand., Angus) would be -1.i lb - 4.2 lb = -5.3 lb. At weaning, the Simmental bull will produce heavier calves. This weight difference becomes more axiomatic at yearling age, when the expected yearling weight of the Simmental bull offspring will surpass the Limousin balderdash offspring by almost 40 lb. On superlative of that, its daughters volition produce, on average, 9.6 lb more milk than the daughters of the Limousin bull. Therefore, the Simmental bull will be easier on heifers (lower birth weight), provide faster growth pre- and post-weaning, and have daughters that produce more milk.

Benefits of genomic testing females

Selecting females for replacement is one of the nearly challenging aspects of commercial cow-dogie production. Also, heifer development is an expensive proffer. Therefore, producers may decide whether a given heifer can be productive and assisting before she has had an opportunity to express productivity associated with profitability, including fertility, calving ease, milking ability, growth and mature size. Past using a good breeding strategy and existence specific virtually option principles, producers can raise the right replacement heifers for the herd to optimize profitability. Genomic testing enables seedstock and commercial beefiness producers to brand more than informed decisions, and with more confidence, and capitalize on animals with superior genetic merit.

Genotyping females can aid producers know where their heifers are genetically, so that they will exist able to brand bull pick with more confidence (Pryce and Hayes, 2012). Focusing on profitability indexes that include wellness traits, operation, carcass quality, and maternal traits, the commercial herd too as the pure breed herd will steepen the genetic progress curve and herd will exist more profitable, creating better genetics long term. Genomic testing is that borderland that allows the states to go the most value with the least amount of inputs through smart option pressures.

It is important to keep in heed that success in the cattle business concern is a function of both genetics and phenotype. The best genetics may all the same occasionally produce offspring with poor anxiety and legs that will not hold up well in pasture or feedlot systems. Understanding how and where the herd is excelling and where changes need to be fabricated tin can assist producers make improvements. Keep in mind that single trait selection, selecting, for example, solely on milk product, is usually a disaster. Cattle genetics must be selected to fit the surroundings and production practices of the operation or the performance they will be marketed to. Know what your market place wants and learn how to provide the type of cattle that fit that market past applying appropriate selection principles.

Summary

For seedstock producers, genomic testing is a no-brainer and the way of the future. The adoption of this technology by seedstock producers has already begun to make up one's mind their success in the market place. For commercial cattlemen, every bit genomic testing costs continue to drop, genotyping females should become increasingly popular to capture extra value.

Herds with a superior genetic profile accept a central advantage over other herds and, in many cases, volition outperform their contemporaries over their lifetime. When young animals are part of a genetic comeback program, the use of GE-EPDs on the bull side and genomic testing on the heifer side are critical. Using skillful selection techniques volition allow producers to select and develop the right replacement heifers and consistently mate them to complementary sires to optimize profitability.

Implications

Call back, EPDs need to be used in conjunction with operation goals and resources. Limited available feed may limit the how aggressively yous select for traits that requires a great deal of inputs and knowing what creates value for your marketplace volition result in focusing on traits that are relevant. Your genetic parameters may be different from someone else based on your environment, so focus on your needs. Remember, cattle must nevertheless be sound structured and reproductive to concluding, abound, and reduce your workload. A balanced approach is crucial for a sustainable enterprise, and that includes making sure that your genetics withal friction match your system with desired physical features that will terminal in your system and run across buyer need.

Bibliography

American Angus Clan. 2020. Combined Value Index - December xiii, 2019 Update Accessed on April 21^st, 2020.

American Angus Association. 2020. Value Indexes. Accessed on April 21^st, 2020.

American Hereford Clan. 2020. Trait Definitions. Accessed on Apr 21^st, 2020.

American Simmental Association. 2020. Quick Reference to ASA EPDs and $ Indexes. Accessed on April 21^st, 2020.

Beefiness Sires by Breed. 2020. Accessed on Apr 16^th, 2020.

Beef Sires Catalog. 2020. Accessed on April xvi^th, 2020.

Garrick, D. J., Golden, B. L. 2009. Producing and genetic evaluations in the United States beef manufacture of today. J. Anim. Sci. 2009, 87: E11-E18. DOI: ten.2527/jas.2008-1431.

Kuehn, L., and Thallman, M. 2019. Beyond-Breed EPD Tabular array and Improvements. Accessed on April 15^th, 2020.

Philipsson, J., K. Banos, and T. Arnason. 1994. Nowadays and futurity uses of selection index methodology in dairy cattle. J. Dairy Sci.77:3252–3261. DOI: 10.3168/jds.S0022-0302(94)77266-0

Pryce, J., Hayes, B. 2012. A review of how dairy farmers can utilize and profit from genomic technologies. Brute Product Science 52, 180-184.

Rolf, M. M., Decker, J. Due east., McKay, S. D., Tizioto, P. C., Branham, K. A., Whitacre, L. Yard., Hoff, J. L., Regitano, L. C. A., Taylor, J. F. Genomics in the U.s.a. beef industry. Livest Sci. 2014;166:84–93. DOI: x.1016/j.livsci.2014.06.005

Van Eenennaam A. L., Drake D. J. 2012. Where in the beef-cattle supply chain might DNA tests generate value? Anim. Prod. Sci. 52:185–96. DOI: 10.1071/AN11060

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Source: https://extension.psu.edu/understanding-epds-and-genomic-testing-in-beef-cattle

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