An article published in Alpaca World Magazine written by Steve Marshall               www.stansburyalpacas.com.au               sojmarshall@internode.on.net

Introduction

Why is one alpaca worth more than another? How am I able to rank and differentiate between several alpacas of slightly varying characteristics? In the show ring Judges must make a decision and rank alpacas based solely on phenotype, that is, the observable, physical characteristics of alpacas presented on a particular day. While show results are significant in identifying elite alpacas, individual environmental conditions influence the presentation of each alpaca. In fact, a Judge may place five alpacas in a completely different order at two shows that are only a few weeks apart. The Judge should not be considered wrong at either show because the Judge makes a decision about their ranking as they appear on that particular day.

What are Estimated Breeding Values?

While ranking alpacas at shows has it’s place, calculating Estimated Breeding Values (EBVs) may be of far more use to a breeder interested in herd improvement. An estimated Breeding Value is quite simply an estimation of the value of a particular alpaca in a particular breeding program. With calculated EBVs a breeder may make more informed decisions about matings that should ultimately lead to greater herd improvement.

Within any alpaca herd there is significant variation and a variety of factors could have influenced the variation you see in the phenotype of each alpaca. The use of estimated breeding values can be an important tool to provide direction when making decisions about a breeding program. EBVs may also be used to determine a monetary value ranking of animals in a herd. There are many different methods and criteria used for calculating EBVs.

Across-herd Genetic Evaluation (AGE)

Possibly the easiest method, and quite suitable for most breeding programs is the Australian Alpaca Association, AGE program. The Across-herd Genetic Evaluation (AGE) program involves supplying data for fleece and other traits and the Association manages the rest, providing the breeder with statistical data for further decision making. The AGE uses (BLUP) Best Linear Unbiased Prediction and is considered possibly the most accurate method of ranking any type of livestock. The AGE program enables ranking of alpacas of different ages, on different properties to be compared and ranked taking into account different environmental and seasonal conditions.

What traits should be measured?

The alpaca industry is in its infancy and aside from the basic breed standard, people are still formulating ideas about what they consider important. How much should you value micron or body weight or fleece coverage? Some EBVs take into account only fleece data, while others have more of a, whole alpaca encompassing approach. Using measurable data such as fleece statistics, body weight, etc, is very objective and helps to maintain accuracy and consistency. However, by using some more subjective information it is possible to take into account the total animal when calculating EBVs. I guess this is more like the problem faced by judges in the show ring. The more you have to make decisions about subjective traits the more likely you are to develop some inconsistency. It is possible to provide some examples, however, what one breeder considers important may not be of such importance to another. The decision about which traits to measure and the weighting given to each should be based on the goals of your particular breeding program

Assessment Rubrics

In recent years there have been a number of very useful articles released detailing specific features to look for when identifying conformation faults. Some are in the form of “breed standards” and have been published by various Alpaca Breeder Associations around the world and are available on web sites. Others are in the form of magazine articles, conference proceedings and scientific research papers. In most cases each document attempts to describe what the author considers the perfect alpaca. When measuring alpacas against these standards it becomes difficult to place a value on specific traits or characteristics according to how perfect the alpaca is because our judgment becomes rather subjective. For example, the Australian Alpaca Association breed standard for Huacaya alpaca states that an alpacas average height should be 90 – 95 cm. When assessing the alpaca’s height for calculation of EBVs, what value should be given if it is within this range and what value outside this range? An even more difficult feature to assess due to it’s subjective nature is fleece coverage on head and legs. One breeder may highly value leg coverage while another considers fleece cover on legs insignificant. Assessment rubrics can be used to maintain objectivity and also maintain a focus on features that a particular breeder finds important. The example rubric below has been constructed for the purpose of this article and has limited detail to measure traits. However any breeder can construct a rubric with descriptors to help maintain consistency when assessing alpacas and applying values for particular traits. The rubric below specifically suits my purposes and each breeder should develop their own rubric assigning values to traits that are of importance in their own breeding program.

In some cases a breeder is only interested in the EBV and could simply add the figures as they go to arrive at a sum total for the EBV. However, a breeder may elect to use a complete page for each alpaca recording the alpacas name and tag details at the top and totals down the right hand side. In this case a record of the value for each trait is retained for future reference. This could be particularly useful in identifying strengths and weaknesses of individual alpacas.

 Example of EBV in practice

At Stansbury Alpacas we use EBVs for a variety of reasons.  For us EBVs must take into account traits that are important to our particular breeding program. Such traits or attributes include, fleece, conformation and inbreeding coefficients for our linebreeding program. An example of criteria we use, traits that we assign values to, and how we calculate an EBV on 18month old alpacas is below.