Ian and Fiona Vanderbeek
Birrong Suri Alpacas
Canyonleigh NSW 2577
Phone: +61 2 4878 9310
Mobile: +61 417 727 146 (Ian)
Mobile: +61 407 850 374 (Fiona)
Fax: +61 2 4878 9360
SURI ALPACA GENETICS MADE SIMPLE
(or how to win at cards!)
To be successful in breeding any livestock, be it cattle, sheep, horses or chickens it is vital to have at least a basic understanding of genetics. This was never more the case than with breeding the suri alpaca. Genetics is the science behind the art of livestock breeding. Without this knowledge the breeder will find it very hard, if not impossible, to make informed purchasing decisions and ensure that each generation of breeding shows an improvement on the previous. Sadly, it is a topic which is often put in the “too hard basket” by many new (and not so new) suri alpaca breeders leading to disappointment and disillusionment.
WHAT IS GENETICS?
Genetics is the study of heredity and the units of inheritance (genes) which are contributed equally by each parent when they mate and produce offspring. One of the most off putting things about beginning to study genetics is the baffling terminology—we will try to explain some of the most important of these concepts in the simplest way. Most of us will understand a little of how blue or brown eyes are inherited in humans and we have used this as an example throughout the definitions:
Most higher forms of animal life reproduce as the result of the mating of a male and a female. Remember: each parent is carrying two copies of every gene. However, during the formation of the female’s egg cell and the male’s sperm cells the two sets of genes divide in half, and then re-join in a new combination when the egg is fertilised and the embryo starts to develop. This results in the offspring having its own unique set of genetic material, inherited in exactly equal amounts from its two parents.
SO, HOW DO WE APPLY ALL THIS THEORY TO THE BREEDING OF SURIS?
The suri is another example of dominance, just like the brown eyed gene in humans. The suri fleece gene is dominant and the huacaya fleece gene is recessive. This means that in order to be a huacaya the alpaca is only carrying huacaya genes. They are “homozygous for the huacaya gene” and if you mate any two huacayas together you will always get a huacaya.
However, because the suri gene is dominant there will be some suris who are “homozygous” and have two suri genes and some who are “heterozygous” and have one suri gene and one huacaya gene. They will look basically the same—that is, they have the same “phenotype” (suri) even though the “genotype” is different.
Try thinking of these genes as pairs of playing cards, placed one on top of another. The card you can see on top indicates the “phenotype”—suri or huacaya—but it is important to know what the “hidden” card is!
What happens when we mate two suris? If both parent animals are homozygous (meaning they only have suri genes), then the offspring will, of course, also be homozygous suris.
If you mate one homozygous suri with one heterozygous suri, you will also always get a suri offspring, but half of them will be heterozygous, having a “hidden” huacaya gene!
If you mate two heterozygous suris, however, you have a 50% chance of producing a heterozygous suri, a 25% chance of producing a homozygous suri but also a one in four chance of actually producing a huacaya!
Many suri breeders will have cross-bred suris within their herd—that is, suris that have a huacaya ancestor somewhere in their background. Again, there are some special terms used to describe these animals:
It is considered by many breeders that by the 4th generation—that is, BC3—a suri can be considered “pure”, having 93.75% suri blood and an 87.5% chance of being homozygous for the suri gene.
Although the fleece of most F1s will not display all the desired characteristics of suri fleece (in particular the lock structure will probably not be as well defined), with each generation of back-crossing the style will usually improve, provided that top-quality, homozygous suri males are used at all times.
Many suri breeders have successfully shown cross-bred animals at even the highest level, when they are regularly to be seen beating “pure” suris in the show ring.
WHY CROSS BREED?
Given the complexities and element of risk described, why do breeders continue to produce cross-bred suris?
But there are disadvantages:
HOW TO WIN THE CROSSING GAME
So, whether the new suri breeder chooses to start with pure bred suris or crosses is an individual decision. Whichever route is chosen, understanding and applying these basic genetic principles can be hugely rewarding as you start to breed your own line of suri, and see the quantum leaps in quality that can be produced with each generation.
If you have any questions about suri genetics or other aspects of alpaca breeding please contact us for further information.