DEP can be complicated and confusing for beginners, to the point where it can become difficult to choose a bull for your herd. But, once you understand how to analyze DEP, it will be of great use to you in determining the choice of a breeding bull or thoroughbred cows for your business.
Normally, Predicted Differences In Offspring, or DEP, are numbers that predict the genetic quality of the future offspring or offspring of a particular bull, cow or heifer. It is a method that helps livestock breeders, livestock replacement (thoroughbreds) or commercial production, to determine whether a particular bull, cow or heifer is sufficient to produce the desired calves which serve to improve the genetic quality of the herd. the herd or the sale of meat to butchers. However, this tool is considered the hardest part of a livestock farm because you have to read, interpret and understand the various numbers and abbreviations for each particular animal. Don't worry - the following steps will make your life easier and less confusing in reading and understanding DEP.
Steps
Step 1. Obtain a catalog of breeding animals or bulls, or even a catalog from an AI (Artificial Insemination) company. You can find them online by contacting several breeding / breeding organizations and receive copies of bull and cow catalogs to control
Local cattle replacement breeders who often do discounts and exhibits are sources from which to get catalogs of bulls and heifers for sale. Different AI companies such as Genex or Semex are good places to go to analyze the different DEPs of bull seeds available for use. Most information on bulls is available online or by ordering a catalog.
Step 2. Find a particular bull, cow or heifer that you like
It doesn't matter which one you choose - the first on the list can too. But you will need to pay attention to the DEP numbers to continue with the steps listed below.
Step 3. Start by looking at the abbreviations found in the DEP chart
The two most common abbreviations are: Production characteristics and accuracy of values. The accuracy of the values is expressed as a positive / negative percentage and is abbreviated to ACC. The production characteristics are the DEPs which are analyzed in the section of a riding bull, cow or heifer. The most common characteristics, their abbreviations and meanings (mainly for breeding bulls) that are often reported on the DEP tables, are the following:
- PN (Weight at Birth): The actual weight of a calf at birth, in kilograms (kg).
- PD (Weaning Weight): Equivalent to 205 days, weight of the calf at the time of weaning (excluding maternal reasons), in kilograms (kg).
- YW (Annual Weight): Calf weight after 365 days (excluding maternal reasons), in kilograms (kg).
- Milk, MM (Breast Milk): Measurement of pre-weaning, kilos attributed to the calf due to breastfeeding. (Note that the term "milk" is inappropriate because the values all measure maternal consequences, of which milk is the fundamental one, but not the only one.)
- CE (Ease of Childbirth): The ease with which the calf is calved. It is expressed as a percentage based on a certain number of unassisted deliveries, the larger positive numbers showing the ease of delivery. This DEP is mainly determined by the weight of the calf. (Characteristic reported in breeding associations such as Gelbvieh and Simmental.)
- CED (Ease of Direct Childbirth): Predict ease of calving when a bull takes apart a heifer. Expressed as a percentage based on unassisted deliveries, the larger positive numbers show the ease of calving for heifers. (Characteristic reported in breeding associations such as Angus, Charolais, Gelbvieh, Hereford, Limousin and Red Angus.)
- CW (Carcass Weight): The weight of the carcass of a progeny, in kilograms (kg). (Feature used in breeding associations such as Angus, Brahman, Brangus, Charolais, Gelbvieh, Hereford, Limousin, Red Angus, Simbrah and Simmental.)
- DOC (Docility): Measures the temperament, stress and unreliability of livestock when handled. (Characteristic mainly reported in breeding associations such as Limousin breed associations, but may also be found in Angus, Salers, Charolais and Maine Anjou.)
- Fat (Fat Toughness): This characteristic is back fat measured along the ribs or between the 12th and 12th ribs. It is used to predict total body fat in order to calculate meat quality. (Characteristic reported in breeding associations such as Angus, Brahman, Brangus, Charolais, Gelbvieh, Red Angus, Simbrah and Simmental.)
- IMF (Intramuscular Fat): Measures differences in intramuscular fat over a 365 day period, fat is measured between the 12th and 13th rib of cattle by ultrasound. (Characteristic reported in breeding associations such as Angus, Charolais [included in marbling EPD] Limousin and Hereford.)
- MB (Fat): Fat measured over a period of 365 days, in USDA (United States Department of Agriculture). This is the fundamental factor for the USDA. This DEP characteristic is also measured for farms outside the US, such as Canada, Australia and South Africa. (Characteristic reported in most breeding associations, such as the Angus, Brahman, Brangus, Charolais, Gelbvieh, Limousin, Red Angus, Simbrah and Simmental.)
- M&G, TM, MWW (Milk and Growth / Breast Milk and Growth, Maternal Total, Maternal Weaning Weight): This trait measures the livestock's ability to transmit milk production and growth to offspring. It predicts weaning (direct and maternal) that will be transmitted to the offspring. It is calculated by adding half the weight at weaning to the weight due to milk ([1/2 WW EPD] + MWW EPD). This characteristic is calculated for all species participating in the analyzes of the NCE (National Cattle Evaluation).
- REA, RE (Rib Area): This area is measured in cm between the 12th and 13th ribs, over a period of 365 days. It is used to predict the amount of muscle in the carcass and is relative to the weight of the carcass itself. (Characteristic reported in breeding associations such as Angus, Brahman, Brangus, Charolais, Gelbvieh, Limousin, Red Angus, Simbrah and Simmental.)
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PS (Scrotal Perimeter): Predicts the scrotal perimeter in cm, sexual capacity and fertility. The scrotal perimeter refers to the puberty of the offspring. (Characteristic reported in breeding associations such as Angus, Brangus, Beefmaster, Charolais, Geblvieh, Hereford and Limousin.)
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Note that not all the characteristics used by various associations such as American Angus Association, American Hereford Association and others have been indicated. Check the associations where you live via the internet (especially if you live outside the US) for more information on DEP and terminology and see the links in the "Sources and Citations" section at the end of the article.
For more information on DEP terminology, including features, have a look at AAA's EPD site https://www.angus.org/Nce/Definitions.aspx. For Hereford DEP terminology, check out the AHA website
Read, Understand, and Use Expected Progeny Differences (EPDs) in Cattle Step 4 Step 4. Analyze the numbers that go with the abbreviations listed above
Based on the characteristics themselves, you always worry if the numbers are too high or low compared to the averages. Be concerned if a bull has too high a BW EPD or a negative SC EPD.
- Remember that there are both values, those of accuracy and those of production.
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Most numbers do not exceed the number 100 or drop below -10, and the accuracy ranges from 0.0 to 1.0 as a percentage.
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Accuracy values are published to indicate the risk a farmer takes in purchasing a particular breeding animal. A progeny number and distribution factor for each breeding animal with available pedigree information. This accuracy indicates how accurate the estimates of an animal's genetic factors are, making it very useful for breeders to determine a reliable DEP.
The higher the accuracy value, the lower the risk of ending up with a different DEP than expected. That said, bulls with low accuracy shouldn't be used much, while those with high values may very well be used as you see fit
Read, Understand, and Use Expected Progeny Differences (EPDs) in Cattle Step 5 Step 5. Get to know and familiarize yourself with the averages of the race values
All DEPs relate to a particular livestock, which is arbitrarily determined over the course of a year. Many of these are achieved by forcing the DEP of all animals of a particular vintage to zero. Thus, the DEPs of animals of a certain year are relative to the genetic mean of animals born in the year of mating.
Note that a DEP of 0.0 is not necessarily the average of all livestock. For example, an Angus born in 2006 with a birth weight of +2.3 would represent the average for the whole year, while a bull with a DEP of 0.0 would represent a lower value than the average
Read, Understand, and Use Expected Progeny Differences (EPDs) in Cattle Step 6 Step 6. Consider the DEP values the next time you buy a bull
Many bulls nowadays have DEP values on them, so that you can study them accurately to determine which animal you want.
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Don't pick a bull at random. You must first analyze it to know its weaknesses. If you find weaknesses, you will also need to find strengths in your potential purchase. In both cases, the bulls are chosen to improve the quality of the offspring in replacing the cattle, or to maximize growth so that the calves can be sold. You can't have both: in other words, you can't have your cake and eat it!
The same goes for the purchase of cows and heifers. You have to choose them to try to improve the herd, even if the most important factor is in the choice of the bull
Advice
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Never compare the DEPs of previous animals with those of current animals. This is because the DEP values change from one analysis to another.
DEPs change over time between breeding associations because producers highlight different characteristics that are useful in identifying the strengths or weaknesses of an offspring
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Identify the breeds and animals (mainly bulls) that will lead the herd in a good direction to optimize production in the available environment.
A breeder must be functional and realistic to carefully select the right type of animals for their livestock
- Always choose considering more features. In other words, when choosing a bull for breeding, don't choose it based on one characteristic alone, such as birth weight or post weaning weight. You have to make sure you choose based on multiple characteristics at the same time if you want to improve the qualities of your herd.
- DEPs of different races do not have to never compare together. In other words, you should never compare the DEP of a Limousin to that of a Charolais because this will confuse you and also because the averages of the values change from one breed to another.
- Always remember that the differences in DEP between two animals (considering the bulls more) is an estimate of the expected differences in the progeny, provided that the rearing was done in optimal conditions using thoroughbred cows. No exception!
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Make sure the DEP is used properly. This means that you have to compare and analyze the DEPs of the same offspring, realizing that the DEPs are only estimates and therefore are subject to change as new information becomes available, and avoid animals with too high or too low values of the characteristics that circles.
Always remember to use common sense when analyzing DEPs; they are tools that can be used to help farmers achieve their goals, especially if used properly
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Determines where in a production chain the offspring are to be marketed. The point changes according to the objectives.
For instance, producers selling calves upon weaning tend to use different sires than those who sell at yearling or slaughter end-points
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Determine your goals based on your livestock, considering the environmental conditions in which it is found.
Take specific notes to uncover weaknesses and identify the benefits of your livestock
Warnings
- Never compare DEPs between two different breeds.
- Do not compare the DEPs of past progeny with those of current progeny.
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DEP is used by a farmer to achieve his herd production goals. It should not be used for the selection of livestock because the values are just numbers that can change over time based on new information available.
Sometimes, it is enough to take a look at the physical characteristics or the conformation to recognize a good breeding animal
- Do not use but the DEP relying on only one feature. Consider multiple characteristics at the same time that will help guide you in choosing an animal.
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