|
What is The G.A.I.N.?
Breeders use these EPDs to guide them in their selection and genetic improvement programs. An alpaca breeder who is a member of The G.A.I.N. 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. What are EPDs? 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 do we figure out EPDs? Alpaca breeders keep records the performance values for polygenic
traits that are important to the viability and value of their animals
(weights, fiber characteristics, etc) and enter all this information
into electronic data entry forms. These forms are entered into The
G.A.I.N. database. The G.A.I.N. 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. As the years go by The G.A.I.N. database will also 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). The BLUP program produces EPD values on every trait for every macho, hembra, and cria in the network. 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. 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 doesn’t 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. How can an alpaca breeder join The G.A.I.N.? It is quick and easy. A breeder submits an Enrollment Form to The G.A.I.N. office. This Form is a simple application that asks a few questions about your contact information, your alpacas, etc. Send this form to The G.A.I.N. office along with your payment, or join electronically on-line with a credit card. All alpaca breeders with ARI or CLAA registered animals can join The G.A.I.N. Calculation of across-herd EPDs, however, is dependent on the establishment of good across-herd genetic linkages. As more alpaca breeders become members and submit their data many more good genetic linkages will be established. This will increase the accuracy and value of the EPDs for all breeders in the network. It is truly a win-win situation for the whole industry. How much does membership is The G.A.I.N. cost? The G.A.I.N. fee structure is very simple and reasonable. Annual
fees are based on two things: (1) a herd charge plus (2) a charge
per each animal in the herd for which EPDs are generated. The herd
charge is $150. The per animal charge is $6.25. The breeders enroll animals with ARI or CLAA registration numbers. They also enroll any alpacas used for breeding that will be registered but have not yet been assigned registration numbers. They also enroll progeny that will not be used for breeding so that the data from these progeny will increase the accuracy of the EPDs for the dam and sire. For example, an alpaca breeder with 10 breeding females, two breeding herdsires, and four crias would pay a total G.A.I.N. fee of $250. (= $150 herd charge plus $6.25 x 16) The breeder would pay this amount via PayPal when completing the Enrollment Form on The G.A.I.N. website, or print out the enrollment form and mail with a check. |
The
G.A.I.N. (The Genetic Alpaca Improvement Program) is a computerized,
performance-based program for genetic evaluation and prediction
of polygenic or quantitative traits which are important to alpaca
breeders. The G.A.I.N. is designed to help alpaca breeders identify
the genetic breeding value of their alpacas for use in their breeding
programs. The G.A.I.N also provides alpaca breeders with accurate,
useful information that they can use to advertise and sell their
breeding stock. The G.A.I.N. uses the most modern, scientifically-proven
technology to measure genetic performance and make predictions about
progeny. 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.
|
The
Genetic Alpaca Improvement Network (G.A.I.N.) |
|
| Copyright 2004 The G.A.I.N. All rights reserved. Site development by Hill Shepherd Marketing Group. |
