Unit 14 "Selecting and Judging of Beef" What Do You Call a Young Cow

Expected progeny differences (EPDs) have been applied to improve the genetics of beef cattle for almost 4 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 brute's actual operation, performance of progeny, operation 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 as a Genomic-enhanced EPD (GE-EPD). Thus, in addition to full-blooded, operation and progeny data, GE-EPDs utilize genomic test for increased reliability of an animate being'due south EPD (Eenennaam and Drake, 2012; Rolf et al., 2014).

Source: American Angus Association

Combined with all available sources of data, GE-EPDs are the best estimate of an fauna'south genetic value as a parent. Genomics let improve accuracies for younger animals and allows a clear picture of genetic traits of interest, especially those that are expensive to measure such as feed efficiency, carcass traits in breeding stock, reproductive traits or maternal traits in bulls.

When a producer buys a young bull that has GE-EPDs, he is ownership with the aforementioned level of confidence in that fauna as i that has already sired betwixt x and 36 calves, depending on the trait. In this way, GE-EPDs increment accuracy in those animals much earlier in their lives. With all these benefits, continue in mind that genomically-enhancing the EPDs does not change how the EPD can be used, it just increases its accuracy.

Table 1. Progeny Equivalents (PE) – Carcass trait PE equate to actual carcass harvest data, not ultrasound scan equivalents.

Trait	PE
Calving Ease Straight	26
Birth Weight	23
Weaning Weight	27
Yearling Weight	23
Dry Matter Intake	12
Yearling Height	17
Scrotal Circumference	15
Docility	12
Claw Angle	10
Pes Angle	ten
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 Fatty	14

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

EPD Accuracy

Accuracy (ACC) reflects the precision of a prediction for a given brute's EPD and provides u.s.a. with a level of confidence for that animal'south genetic merit. Bulls with greater accuracy values may exist chosen "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 unlike amongst breeds is of import; some breeds employ an average within a specific twelvemonth, whereas other breeds use a nonspecific historical point.

To improve the accurateness of EPDs for younger bulls, producers may collect and submit Dna samples, which, depending on the trait, may equates to about 10 progeny records for a sire with no other progeny records contributing to his EPDs. Equally more than progeny information are obtained for a sire, the relative contribution of genomic data to overall EPD accurateness is reduced.

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

How to Use EPDs

Before getting started with EPDs, producers should define their specific production goals first and then select based on the EPDs that will best allow them to run across those production goals. For instance, 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 use EPDs based on the selection of breeding bulls that encounter their personal production goals.

Hither are some traits that tin can exist used past those producers who sell the entire dogie crop at weaning or following a backgrounding phase:

• Nascence 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 volition exist sold as feeders.

For producers who retain replacement heifers, the following EPDs are often used in addition to the previous list:

• Calving Ease Total 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&G);
• Mature Weight (MW) or Mature Cow Weight (MCW);
• Maintenance Energy (ME);
• Heifer Pregnancy (HP or HPG);
• Stayability (STAY);
• Mature Height (MH);
• Scrotal Circumference (SC or SCR).

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

Producers who raise their ain animals through the feedlot volition oftentimes focus on the traits below, in addition to the maternal traits previously mentioned:

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

In this case, the traits selected are value traits for cattle marketed at the terminate of life.

Instance 1 of Using EPDs for Bull Selection

In this case, a producer is looking for a Charolais bull to use on blackness Angus-influenced cows that take had at least two calves. In this case, the producer is using the Charolais in what is called a last cross, all calves being sold at weaning or later on a backgrounding menses for slaughter. The producer wishes to maintain calving ease and have the benefit of enhanced weight at the time of sale. Based on the table beneath, which bull would be more appropriate for the stated purpose based on EPD values?

Tabular array 1. Charolais bulls¹ for utilise on mature crossbred females.

Bull	CE	BW	WW	YW	MCE	MILK	SCR	CW	REA	Fatty	MARB
A	11.6	-four	27	58	three.9	23	1.one	20	0.66	0.041	0.18
B	2.9	three	59	99	2.2	1	two.1	49	0.96	0.041	0.22
Breed Average	three.1	0.7	24.4	43.8	4	7.9	0.half dozen	14.7	0.26	0.002	0.04

¹Bulls information retrieved from Select Sires Beefiness and Genex.

With the focus on this phase of production, emphasis should be given mainly to three traits: CE, BW, and WW. We are assuming that these bulls are most likely young and have low accuracies, or are not proven.

Calving ease (CE) relates directly to the bull's pressure level on nascence weight. Bull B is expected, on boilerplate, to accept 8.7 percent fewer unassisted births when bred to two-year-one-time heifers than Bull A (a disadvantage if breeding to heifers). Balderdash B has an expected birth weight that would be seven pounds heavier, on average, than Balderdash A. Thus, while articulate that Bull A would be more than appropriate for breeding heifers, our producer is interested in breeding multiparous cows. Therefore, because bull B has a BW EPD that is only 2.3 lb. heavier than the breed boilerplate, the producer likely will want to put their emphasis on other traits. Examination of the WW EPD indicated that Bull B would be expected to produce calves that are 32 pounds heavier at weaning, on average, than Bull A. This difference is what commonly drives sales and profits at weaning. Thus, if the producer decides to sell calves at weaning time, Balderdash B may be the appropriate choice. In addition, while perhaps non as important if the producer sells at weaning, this producer may as well 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 around yearling historic period and through the feedlot may create a reputation of raising high-value calves that are assisting for feedlot owners. Considering this is a final cross, no heifers will be retained, and maternal traits can be ignored.

Selection by Index

Now, in add-on to private trait selection using EPDs, animals can too be selected on an "index". An economic alphabetize 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 economical values equally well every bit the relationships between 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 among their phenotypes and genotypes, simultaneous multiple-trait alphabetize option has been more effective than contained culling levels or sequential selection (Philipsson et al., 1994; Garrick and Golden, 2009).

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

From the American Angus Association (AAA, 2020):

• Beefiness Value ($B), an index value expressed in dollars per head, is the expected average departure in future progeny functioning for postweaning and carcass value.
• Combined Value ($C), expressed in dollars per head, is an alphabetize which includes all traits that make up both Maternal Weaned Dogie Value ($G) and Beefiness Value ($B) with the objective that commercial producers volition supplant 20% of their breeding females per year with replacement heifers retained within their own herd.

From the American Hereford Clan (AHA, 2020):

• Baldy Maternal Index (BMI$) is an index to maximize profit for commercial cow-calf producers who use Hereford bulls in rotational crossbreeding programs on Angus-based cows.
• Certified Hereford Beef Index (CHB$) is a last sire alphabetize 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 Alphabetize (API) is an index that evaluates sires for use on the unabridged cow herd (bred to Angus first-calf 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.
• Last Alphabetize (TI) is an alphabetize that evaluates sires for utilize on mature Angus cows, with all offspring put on feed and sold on grade and yield.

Instance 2 of Using EPDs for Bull Selection

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

Tabular array 2. Angus bulls^ane for use on straight-bred Angus females.

Bull	CED	BW	WW	YW	CW	Marb	RE	Fatty	$M	$W	$F	$G	$B
A	16	-0.6	68	129	62	1.eight	1.eleven	-0.028	62	79	124	120	244
B	16	-2.5	64	118	32	0.42	0.53	0.046	51	78	69	38	106
Brood Boilerplate2	3	1	26	45	22	0.42	0.32	0.008	52	54	82	44	126

¹Bulls information retrieved from Select Sires Beef.
^twoBreed average retrieved from The American Angus Association.

To accost the producer'south goal as stated, we can await at the Maternal Weaned Calf Value ($M) because it provides an indication of expected maternal ability and turn a profit based on auction of weaned calves. Bull A will produce calves that will turn a profit, on average, $eleven more than Bull B using the $K. Bull A will be the better purchase for this scenario where female retention and weaned calf value are both important.

Beyond-breed EPD Comparisons

Within a breed, EPDs can be directly compared. Bulls of unlike breeds can likewise be compared, but aligning factors to the EPDs are needed because an EPD from one brood evaluation is not directly comparable to an EPD from another brood evaluation. Since 1993, the U.South. Meat Animal Research Center (USMARC) has produced a tabular array of these adjustment factors and so that the merit of individuals can exist compared across breeds.

Instance iii of Using EPDs for Bull Selection

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

Table three. DEPs from different breeds to utilise on a commercial crossbred herd.

Bull	CE	BW	WW	YW	Milk	DOC	YG	CW	REA	Marb
Simmental1	17.1	-iii.ix	68	95.7	26.3	7.iv	-0.22	28.2	0.58	0.35
Limousini	fourteen	1.7	61	xc	21	8	-0.73	xvi	1.23	eight

¹Bulls information retrieved from Select Sires Beef.

With the in a higher place data, the producer likewise needs to access the table below:

Table 4. Adjustment Factors to Estimate beyond-breed EPDs.

Brood	Nascency Wt. (lb)	Weaning WT. (lb)	Yearling Wt. (lb)	Maternal Milk (lb)	Marbling Scorea	Ribeye Surface 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	1.iv	-16.5	-44.4	-12.five	-0.30	0.02	-0.073	-71.1
Red Angus	2.6	-19.4	-31.4	one.5	-0.03	0.25	-0.040	-13.2
Shorthorn	4.five	-34.iv	-46.6	-0.i	-0.07	0.47	-0.032	5.6
S Devon	2.vi	-29.ix	-55.4	3.ane	-0.53	0.64	-0.213	-68.eight
Beefmaster	4.0	23.4	1.i	seven.7
Brahman	10.3	53.3	14.4	16.vii		0.03	-0.166	-35.ix
Brangus	3.1	14.9	5.three	12.ix
Santa Gertrudis	5.2	twoscore.4	39.eight	xvi.viii	-0.44	0.12	-0.085	-12.3
Braunvieh	2.2	-21.one	-46.6	4.1	-0.61	i.00	-0.100	-53.4
Charolais	6.6	32.7	23.2	8.ane	-0.29	0.79	-0.201	five.one
Chiangu	2.8	-21.i	-36.2	2.five	-0.47	0.59	-0.142	-nineteen.3
Gelbvieh	two.9	-15.v	-27.one	viii.2	-0.37	0.66	-0.066	1.v
Limousin	two.5	-16.9	-53.9	-ii.4	-0.03	0.59	-0.024	-5.ane
Maine-Anjou	2.iv	-xxx.3	-55.2	-7.0	-0.43	0.95	-0.179	-35.1
Salers	0.9	-eleven.2	-48.0	5.6	0.07	1.08	-0.177	-47.vi
Simmental	2.8	-11.6	-19.2	1.8	-0.12	0.45	-0.049	-7.five
Tarentaise	2.7	xx.2	-12.1	15.7

^aMarbling score units: 4.00 = s1°0; v.00 = Sm00
Source: US Meat Fauna Inquiry Center (2020) through Beef Improvement Federation.

With both tables of information, a table for across brood comparisons tin exist made, like to Table 5.

Table 5. Example of using beyond-brood aligning factors to catechumen noncomparable within-breed EPDs to comparable across-breed EPDs.

Bull		BW (lb)	WW (lb)	YW (lb)	Milk (lb)
Simmental	EPDane	-3.ix	68	95.7	26.3
	AB Adj. Factorstwo	two.viii	-11.6	19.two	ane.8
	AB-EPD3	-1.ane	56.4	76.5	28.1
Limousin	EPD1	one.seven	61	90	21
	AB Adj. Factorstwo	two.5	-16.nine	-53.nine	-2.4
	AB-EPDiii	four.two	44.ane	36.1	18.6

¹EPDs are the inside-breed EPD values from the brood'due south genetic evaluation for the bull of interest.
²AB adj. factors are the across-breed adjustment factors from Table ane.
ⁱⁱⁱAcross-brood EPDs subsequently adjustment factors are applied to within-breed EPDs.

The across-breed (AB) adjustment factors for BW are ii.8 lb for Simmental sires and 2.5 lb for Limousin sires. The AB-EPD for that trait is -3.ix lb + ii.8 lb = -1.1 lb for the Simmental bull and 1.7 lb + 2.5 lb = iv.2 lb for the Limousin bull. The expected nascence weight deviation of offspring when both are mated to cows of another breed (e.g., Angus) would exist -1.ane lb - 4.2 lb = -5.3 lb. At weaning, the Simmental bull will produce heavier calves. This weight difference becomes more evident at yearling age, when the expected yearling weight of the Simmental bull offspring volition surpass the Limousin bull offspring by almost 40 lb. On top of that, its daughters will produce, on average, 9.6 lb more milk than the daughters of the Limousin bull. Therefore, the Simmental bull will exist 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 most challenging aspects of commercial cow-calf production. Also, heifer development is an expensive proposition. Therefore, producers may determine whether a given heifer tin be productive and profitable before she has had an opportunity to express productivity associated with profitability, including fertility, calving ease, milking power, growth and mature size. By using a good breeding strategy and being specific most 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 informed decisions, and with more confidence, and capitalize on animals with superior genetic merit.

Genotyping females can help producers know where their heifers are genetically, so that they will be able to brand bull option with more than confidence (Pryce and Hayes, 2012). Focusing on profitability indexes that include health traits, functioning, carcass quality, and maternal traits, the commercial herd besides as the pure breed herd will steepen the genetic progress curve and herd volition be more profitable, creating amend genetics long term. Genomic testing is that frontier that allows us to go the most value with the least amount of inputs through smart option pressures.

It is of import to keep in mind that success in the cattle business organisation is a function of both genetics and phenotype. The best genetics may even so occasionally produce offspring with poor feet and legs that will not hold up well in pasture or feedlot systems. Agreement how and where the herd is excelling and where changes need to be fabricated can assistance producers brand improvements. Go on in mind that single trait selection, selecting, for instance, solely on milk product, is usually a disaster. Cattle genetics must be selected to fit the environment and production practices of the functioning or the operation they volition exist marketed to. Know what your market wants and acquire 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 futurity. The adoption of this applied science by seedstock producers has already begun to determine their success in the market. For commercial cattlemen, equally genomic testing costs continue to drop, genotyping females should become increasingly pop to capture extra value.

Herds with a superior genetic contour have a fundamental advantage over other herds and, in many cases, will 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 choice techniques will allow producers to select and develop the right replacement heifers and consistently mate them to complementary sires to optimize profitability.

Implications

Recollect, EPDs need to exist used in conjunction with performance goals and resources. Limited available feed may limit the how aggressively you select for traits that requires a not bad bargain of inputs and knowing what creates value for your marketplace volition result in focusing on traits that are relevant. Your genetic parameters may be dissimilar from someone else based on your environment, and so focus on your needs. Remember, cattle must still be audio structured and reproductive to last, abound, and reduce your workload. A balanced approach is crucial for a sustainable enterprise, and that includes making sure that your genetics even so friction match your arrangement with desired physical features that will last in your system and meet buyer demand.

Bibliography

American Angus Association. 2020. Combined Value Index - December 13, 2019 Update Accessed on April 21^st, 2020.

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

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

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

Beef Sires past Breed. 2020. Accessed on April 16^th, 2020.

Beef Sires Catalog. 2020. Accessed on Apr 16^thursday, 2020.

Garrick, D. J., Golden, B. 50. 2009. Producing and genetic evaluations in the United states beef industry of today. J. Anim. Sci. 2009, 87: E11-E18. DOI: 10.2527/jas.2008-1431.

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

Philipsson, J., G. Banos, and T. Arnason. 1994. Present and future 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 Production Scientific discipline 52, 180-184.

Rolf, M. M., Decker, J. E., McKay, S. D., Tizioto, P. C., Branham, 1000. A., Whitacre, L. One thousand., Hoff, J. L., Regitano, L. C. A., Taylor, J. F. Genomics in the Usa beef industry. Livest Sci. 2014;166:84–93. DOI: ten.1016/j.livsci.2014.06.005

Van Eenennaam A. L., Drake D. J. 2012. Where in the beef-cattle supply concatenation might Deoxyribonucleic acid 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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