Estimated Progeny Differences (EPDs) are being discussed more frequently within the alpaca community these days. EPD programs are used in many, if not most, of the world's livestock industries to assist breeders with improving their herds. The basis of every EPD program is a focus on measurable traits and the recording of selected measurements for related animals. Once enough measurements have been gathered, statistical analysis is used to create predictions that allow breeders to determine which animals are more successfully producing the desired traits.
As announced in February following input from members for our strategic plan, ARI has been investigating the possible implementation of such a program. It was important that we first determine the resources necessary to accomplish such a task. Now, we move on to determining the specific interest in this service and what needs to be included. In order to accomplish this, the ARI Board is pleased to announce the establishment of an ad hoc EPD (Estimated Progeny Difference) Development Committee to evaluate and develop a plan for an EPD program for ARI member use.

The ARI EPD Development Committee has a mission to:
• Create a Member Survey to establish member needs and interest in an EPD system
• Educate members regarding the purpose, usefulness and methods of an EPD system
• Outline a potential EPD program for alpacas
• Provide the ARI Board with a recommendation on moving forward and an implementation plan

The committee members are Dr. Wayne Jarvis, Dr. Dick Walker, Mr. David Barboza, and from the ARI Board Ms. Deb Hill, Mr. Wayne Robinson and Dr. Shauna Brummet who will chair the committee. The committee will draw on the advice of key scientific and livestock industry experts as needed to assist in the evaluation and development of an EPD system for alpacas.

Using this advice in conjunction with the comments from the membership, the committee will make a recommendation to the Board.

We look forward to engaging the ARI Membership in this very important industry development.
Sincerely,
ARI Board of Directors
Bruce Beatty, Shauna Brummet, Donna Christley, Lucy Farrar,
Deb Hill, Jim King, and Wayne Robinson

The llama-like creatures act as bouncers on his farm near Tetbury, in Gloucestershire, bonding with the sheep, ever ready to protect them against predators such as foxes, which used to kill as many as 50 newborn lambs every year.

Unlike sheep, alpacas happily confront foxes, chase them and try to trample or kick them. And while the prince’s staff have not yet found any battered fox bodies in the hedgerows, they haven’t lost any lambs either since the alpacas arrived.

Alpacas, which are related to camels, are domestic animals first bred from wild vicuna in South America. They are edible when young but are reared mainly for their fine wool. They look like a cross between a small llama and a large, long-necked sheep and can grow to 6ft tall.

Duchy Home Farm has been run organically since 1986 and is renowned as one of the most environmentally friendly farms in the country.

Foxes, though, are a serious problem. Until 2005, when the ban came into force, the Beaufort hunt helped to control the fox population in rural areas of Gloucestershire.

The new laws did not, in fact, outlaw the extermination of foxes by other methods such as shooting. They may also be hunted with other species. The Warwickshire hunt even experimented with giant eagle owls.

Charles’s alpacas do not hunt. Instead, they are used as sentries, standing guard over his collection of sheep, which includes some valuable rare breeds. If one spots a fox, they all charge over to administer a group kicking.

All four animals are male geldings, worth about £500 each. Breeding animals are too valuable for such work, with pregnant females fetching £3,500 or more and stud males worth up to £30,000 depending on pedigree.

Rob Bettinson, former president of the British Alpaca Society and now owner of Toft Alpacas, keeps a breeding herd of 150 on his farm in Dunchurch, Warwickshire. “Alpacas were introduced to Britain only about 12 years ago but the national herd is now 17,000 strong,” Bettinson said. “They are popular as pets and for breeding and farmers increasingly use them as sentries to guard other animals.

“If a fox enters the field they will all start walking or running towards it. Alpaca can kick and trample very hard so the fox usually gets the message pretty quickly and clears out.”

Such protective behaviour seems instinctive to alpacas, which appear to bond with any animals grazing with them in the field. Farmers have reported watching alpacas rounding up sheep and chickens and then standing guard over them when danger looms.

They may have their work cut out on the prince’s farm. There are an estimated 240,000 adult foxes in Britain and 425,000 cubs are born each year.

Because the adult population is fairly stable, this means that about 425,000 foxes die each year – mostly through disease, starvation and road accidents.

In rural areas gamekeepers kill about 75,000 a year. Hunts, when legal, killed about 16,000.

Richard Kempsey, production manager at Clarence Court, a company producing speciality eggs from birds including ostriches, geese, ducks and rare breeds of hens, suffered years of predation at his farm near Truro, in Cornwall, until he bought two alpacas.

He said: “We have 2,000 birds on site and the foxes are desperate to get at them but the alpaca keep them away. We have named them William and Harry.”

The Royal Society for the Prevention of Cruelty to Animals was nonplussed when asked whether using alpacas was cruel to foxes. “Using an imported South American camel to chase British foxes is so bizarre, we have not even thought about it,” said John Rolls, the society’s director of communications.

A fox’s worst nightmare

- Alpacas are fluffy and sociable but can be fierce. They chase away intruders and some spit globules of semi-digested vegetation mixed with stomach acid

- They live in families consisting of a single male, several females and young, known as cria

- They originate from the Peruvian Andes, where they thrive at altitudes of 10,000-15,000ft

What are EPDs?

This technology -- called Estimated Progeny Differences, or sometimes called Estimated Transmitting Ability -- has been used extensively in the beef cattle, dairy, swine, poultry and sheep industries for many years, and is only now being implemented in the alpaca industry. The important points here are that we don’t have to reinvent the wheel and we don’t have to wonder if this technology actually works. Breeders use these EPDs to guide them in their selection and genetic improvement programs. If implemented, an alpaca breeder receives reports on the genetic values for every animal in their herd, based on the performances of those animals and all the animals that are genetically related to them, over many years and management systems. The breeder then uses these EPDs to increase their Selection Accuracy and make the best mating decisions for the goals of their own specific breeding program and thus substantially improve their rate of genetic gain towards those goals.

EPDs allow a breeder to rank all the animals in the herd by genetic value, identify the animals that will be most predictable at producing the desired results in the next generation, and to decide which animals to sell to their customers based on the customers breeding goals.

Estimated breeding value, EBV, is a way of estimating the genetic value of a parent. However, we often prefer to think of what will the effect of using this particular parent be on the offspring. In other words, how much better than average will Mr. Studly’s offspring be for a particular trait. This is referred to as the Estimated Progeny Difference (EPD) or some geneticists use the term Estimated Transmitting Ability (ETA). Since each parent can only contribute ½ of its genes to the offspring, then on average that parent only passes on ½ of its breeding value to the offspring. So one half of the parents breeding value is the estimated progeny difference.

How will we figure out EPDs?

Alpaca breeders keep records on the performance values for polygenic traits that are important to the viability and value of their animals (weights, fiber characteristics, etc) and will enter all this information into a software application that could be added to ARI’s current system. The ARI computer then identifies the genetic linkages between these animals and across years -- like when sires are sold or traded, or when progeny are distributed into many other herds -- and puts this data into one massive calculation for all of the alpacas in the network. This calculation will vary based on the traits that are determined to be important by alpaca breeders to determine the EPD. As time progresses, this database of traits will begin to include all the data from previous years, for all the relatives, across all generations. The EPD calculations even include data from related traits, because an animal's performance in any trait gives information on how it will perform in a similar trait (for example, a good preweaning weight for a fast-growing cria suggests it will also have a good postweaning weight). Each EPD for each animal is recalculated annually once the new data from each new year’s crias, fleece measurements, etc. are entered into the system. Therefore, an alpaca’s EPD could change over time as more data is gained on the alpacas in its pedigree.

What do EPDs look like?

EPDs are given in the normal units of a trait. For example +0.8 pounds (for weights) or perhaps -0.3 microns (for fiber diameter). We must understand that an EPD value is not a ratio or an index. EPDs are expressed as differences (+ or -) from the population mean. Thus, EPDs are always reported as a positive (+) or negative (-) number.

The positive or negative symbols d not necessarily always mean better or worse -- it depends on the trait. For example, a Fleece Weight EPD of +0.7 pounds is good (i.e. more fleece produced at shearing), but an Average Fiber Diameter EPD of -0.5 microns would also be good (i.e. smaller diameter fiber, which is more valuable to fine fiber users).

We can then compare alpacas with positive and negative EPDs, or we can use EPD values to compare animals who both have positive EPDs. For example, a sire with a Fleece Weight EPD of +1.0 lb is good, but a different sire with a Fleece Weight EPD of +2.0 lbs is better. (Assuming of course that we want the offspring to produce more fleece than the parents). EPDs are a new concept to most alpaca breeders, but once you get used to them, they give the most objective and reliable estimation of genetic value possible.