HaSu Establishes New Breeding Tools - EPDs

Date: 09/27/2006
By: HaSu Ranch: Susan Muther and Hazen Reed
Link: hasu.biz/index.cfm?fuseaction=feature.display&feature_id=175
Copyright: HaSu Ranch Alpacas
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Alpacas produce some of the world's most luxurious and soft natural fibers. Every year, once the snows and biting cold winds have surrendered their grip on our mountain top, we shear our alpacas of their year's fleece. This is always an exciting time around the farm, but this year, we are especially excited. This year, for the first time, we have tools available to us that have never before been available in the alpaca industry. No, the tools are not the latest in super-alloy, liquid-cooled electric shears. What's new this year is that we can finally use the power of statistical analysis available to other livestock breeds for decades to begin assessing the effectiveness of our alpaca breeding choices. The new tools we have are known to top commercial livestock breeding industries of dairy cattle, fiber sheep and beef cattle, among others. These tools have been employed to assist breeders in making informed breeding decisions that help guide their breeding programs to higher and higher levels of success. What these breeders understand and use is the techniques collectively referred to as Expected Progeny Difference, or EPD for short.

What is an EPD? Back in the early 1970's, enterprising cattle breeders developed genetic evaluation techniques that have now become common-place in modern breeding programs. Sheep breeders, for example, regularly use performance records like average fiber diameter, total annual fleece weight and annual staple length to calculate EPDs for animals in their herds. With EPDs in hand, sheep producers can more effectively evaluate the potential of one animal over another to pass positive traits on to progeny. The comprehensive analysis of the performance records of large numbers of animals from a single breed produces numeric indicators for the herd or flock as a whole. Individual animals from the herd can have EPDs or Expected Progeny Differences calculated for these same traits. Usually expressed as some amount over or under that of the herd average, these EPDs help producers determine the potential of one animal to pass specific traits on to their off-spring.

Expected progeny differences (EPDs) are used to provide estimates of the relative genetic value of individual animals for specific traits. While it is simply too early to know for sure what traits are even worthy of consideration in alpacas, we are examining the commercially important traits of the animals fleece and their potential to be passed from parent to off-spring. Specifically, differences in EPDs between alpacas predict differences in performance between their future offspring. What we hope EPDs will give us is information that will allow us to choose males, that when bred to animals of the same average genetic merit, will produce cria with consistently better traits, like total fleece weight or fineness. EPDs are calculated for other breeds for animal size, milk production and other traits. In alpacas, we are looking solely at fleece traits like average fiber diameter and mean staple length. EPDs are reported in the same units of measurement as the trait, so for fiber diameter, we use microns.

Now, thanks to the incredible staff at BreedWorks and our partner Mike Safley, the Ideal Alpaca Community has the alpaca industry's first practical methodology for the creation and use of EPDs. The Ideal Alpaca Community is a group of breeders who share a collective purpose to raise genetically superior alpacas that produce high volumes of fine fleece. BreedWorks and HaSu have been intimately involved in the branding, marketing, and development of this organization because we strongly support its goals. Along with the skilled and experienced staff of Yocom-McColl Testing Labs, and the professional guidance of Dr. David Notter of the College of Agriculture and Life Sciences at Virginia Tech, we can start to truly evaluate our alpacas' breeding values (ABVs).

This year, the Ideal-Alpaca Community web site will begin offering its members access to these incredible predictive tools. Through the use of the online shearing manager software, our shearing will be easier and better organized than ever before. The shearing manager helps make it simple to collect all the vital information required to process the fiber samples. Because the fiber testing process is more involved, the shearing manager will help guide us through the steps to make sure that the testing lab has what it needs from our alpacas. The easy-to-print forms are pre-addressed and labeled for each animal in our herd and ready to be mailed off to Yocom-McColl the day after shearing.

Once the fleece samples arrive at the testing lab, they will be submitted for numerous tests, measuring fiber diameter, over-all length of fiber and a total of 9 other measurements. The resulting report or histogram data is the raw material that will be sent automatically to the genetic evaluation experts at Virginia Tech for the eventual calculation of the alpaca's EPDs or, as we like to say ABVs.

According to the genetic experts at Virginia Tech, breeding value is defined as the value of an individual as a parent.

"Parents transfer a random sample of their genes to their offspring. Estimated breeding value gives an estimate of the transmitting ability of the parent.

One-half the estimated breeding value is equal to the Expected Progeny Difference (EPD). The word difference implies a comparison. Thus, EPDs let us compare or rank the superiority of individual animals. EPDs provide a prediction of future progeny performance of one individual compared to another individual within a breed for a specific trait. The EPDs are reported in plus or minus values in the units of measurement for the trait."

So, an alpacas' EPD for the trait of mean fiber diameter, or MFD, may be 0 (average), +1 or -1, or greater. It will become important to know whether a positive value for a trait is a good thing or not because EPDs are predictions of cria performance. In other words, for MFD, a negative number EPD will indicate a likelihood of producing a cria with a lower than average MFD.

Like other pure-bred livestock industries, we can now employ the powerful predictive techniques contained in EPDs as a genetic selection tool. The use of EPDs has helped guide sire selections and assists in the fair comparisons of progeny performance for selected traits in many breeds. It is with great anticipation that we look to the results of this year's shearing production records from our herd. With this performance data and the resulting EPDs, we expect to increase our ability to predict future cria performance significantly. We know this is not an overnight activity, it has taken other breed organizations many years to develop the techniques and properly apply the results to their own breeding programs, but we are incredibly fortunate to now have the foundation in place that will make the eventual use of EPDs within the alpaca breeding community a real and vital part of our breeding program.