AN INTRODUCTION TO ALPACA GENETICS

When I was first asked to do this article I thought long and hard as I feel as a farmer or lifetime time animal breeder that the alpaca industry complicates the issue of genetics.

Genetics is the study of heredity and the units of inheritance (genes) and was founded by Gregor Mendel, who published his research in 1865-69.

A rudimentary understanding of genetics is of assistance in the process of breeding animals. Thus I will attempt to describe or define some of the unfamiliar terms that will help us understand some of the basic genetic theories that could be applied to alpaca breeding.

A gene is a unit of inheritance, a segment of DNA that occupies a specific place on a chromosome.

DNA (deoxyribonucleic acid) contains all the information in a chemical code needed to build a living organism.

Chromosomes are long stringy aggregates of genes that carry heredity information. Gender is determined by the presence or absence of certain chromosomes.

An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome. Animals have two alleles for each trait. In homozygous animals the alleles are identical. In heterozygous animals the alleles are different.

However there are two forms of homozygosity. Animals homozygous for a particular trait can be either homozygous for the dominant allele or homozygous for the recessive allele.

Dominance describes the effects of the different alleles of a particular gene on the appearance of an organism. If an organism inherits two alleles that are at odds with one another, and the appearance of the organism is determined completely by one of the alleles, then that allele is said to be dominant (eg: Polled cattle, as the polled allele is dominant over the horned allele in cattle).

The genetics of an alpaca are the units of inheritance or genes that an alpaca possesses measurable by looking at its pedigree and by studying its close relatives. Thus the term genotype describes the exact genetic makeup of an individual alpaca, and the term phenotype is the description of the alpaca you actually see in front of you influenced by environmental conditions.

What is the point of all this waffle on genetics in relation to alpacas? Well the so-called Suri fleece gene in alpacas is said to be dominant over the huacaya fleece gene. The fleece type gene is said to have two alleles, one dominant over the other, with the Suri allele dominant over the recessive huacaya allele. This means that in order to have a huacaya fleece an alpaca must be homozygous for the huacaya allele.

I am no scientist but I question these findings, based on what I have seen over almost twenty years of breeding and crossbreeding alpacas. I ask the question if the Suri fleece is dominant how come there are many more huacaya than Suri?. I have seen many alpacas that I would consider to be neither Suri nor huacaya but somewhere in between. However these animals have been registered as either one or the other. Some of the original alpacas that were used to make these findings of dominance as far as I am concerned were in the indeterminable or middle of the range (50% Suri, 50% huacaya phenotype category). To back this up I was told by Americans when I judged in the USA in 2001 that they considered about 10% of their Suri threw huacaya offspring and 2% of the huacayas threw Suri offspring.

I would consider they could fall into an incomplete dominance group where some alleles are neither dominant nor recessive. In such cases, both alleles affect the phenotype of the heterozygote. Sometimes the result is an intermediate phenotype, such as when a snapdragon plant producing red flowers is crossed with one producing white flowers the result is a heterozygous plant producing pink flowers. However the answer to the above questions may be more complicated than we realise.

As a farmer the nearest comparison in livestock I can give as an example of how Suri crossing might work is the first cross Merino/ Border Leicester sheep bred commonly to produce fat lambs. These sheep look like they are, half Merino half Border Leicester.

How do you know if a suri (usually male) is so called homozygous. I prefer the term well bred, in other words his genes are as pure suri as you can get. The theory is that you mate him to 10 huacaya females and if you get 10 suris you are 99.9% sure he is homozygous. I again ask the question do we know the 10 so called huacaya females don't have suri blood in them. The point I am trying to make is that the more well bred an alpaca is the more it will breed true to type, not whether it is homozygous or not.

Now to clarify a point, I too have had wonderful results by using a top Suri male over a so-called huacaya. In fact they have gone on to win championships at shows over so-called pure suris. I feel this is where the secret lies, the original imports of huacaya alpacas from Chile contained a lot more suri blood than we were originally aware. Thus the so-called first crosses could have contained much more than 50% suri genes. I think Dr Pierre Baychelier puts it in the right terms in his article Homozygous Suris in Alpaca Breeding. To be perfectly correct from a statistical point of view, a suri can be proven heterozygous, whereas it can never be proven homozygous. As soon as a suri has one huacaya in its progeny, one can be absolutely sure that the suri is heterozygous — as long as this is not a registration mistake. However, suri cannot be proven homozygous. It is only possible to return a probability of being homozygous, and this probability never reaches 100% although it can be very close.

After all this you would think that I am against crosses suris up from huacayas. Just the opposite, I am all for it and have seen some exciting results from the crosses. The only problem I have with crossing up is the terminology used. I would prefer each cross to have a consistent terminology eg: first cross, second cross, third cross and fourth cross. This is always assuming a purebred male is used, and that all suris out of South America are purebred and this is questionable.

In the Angora goat industry you could breed up from any old goat but it took five generations to have a purebred doe (female) and six generations for a buck (male). A purebred buck had to be used at all times and after all the crossing the fifth generation does were inspected and either registered as pure or made go another cross and inspected again. I feel this system is a little bit harsh and perhaps we don't need it, but new breeders need to be aware of what they are buying and need to thoroughly check the pedigree. The new breeder may be quite happy buying a first cross, as it should be priced accordingly. I would also question how a first cross (F1) (50% suri) bred to another first cross (F1) (50% suri) produces an offspring called an F2. In reality it has no more suri genetics than its parents, and is still technically an F1 (50% suri) (25% is passed on from each parent). In other livestock the offspring would be classed as an F1.

The backcrossing terminology is reasonably accurate provided only purebred suri males are used (eg: F1 x pure = BC1, BC1 x pure = BC2 & so on). Perhaps to stop confusion and because so many crossbred suri males are used, the pedigrees of animals being registered as suris should show the percentage of suri genetics that animal contains.

Advantages of crossing Suri & Huacaya

  1. Cost — Top quality suri females are expensive.
  2. Colour — it is difficult to source coloured suris, so crossbreeding is a way of achieving this.
  3. New genetics — This enables us to widen the suri gene pool.

Disadvantages of crossing Suri & Huacaya

The main disadvantage is the time taken to breed up, and the fact that perhaps the males bred in the upgrade should not be used as sires.

Ultimately it is the breeder's choice given all the facts as to whether they breed up from huacayas or breed pure suris.

COLOUR

Colour genetics in alpacas is an inexact science and we still have a lot to learn. There are some studies out there but once again they have been based on flawed information: the database. By that I mean when an alpaca is registered its colour is stated on the pedigree. If an alpaca is one solid colour (eg: white or black) it should be registered as such but often the solid is omitted for one reason or another. In this case it is therefore assumed by anyone using this information the alpaca has more than one colour on it. The other problem is that people see colour differently and may register an alpaca as dark brown when it is black or vice versa. In spite of this there is a study by Wall & Cole that may be of assistance as they have analysed the colour of more than 10,000 alpacas from the AAA database. My thoughts once again is to study pedigrees and get around and see as many alpacas as you can on farm or at shows and analyse their backgrounds and you will know certain colours emerging from certain bloodlines. No colour seems to be dominant but some males are dominant for particular colours.

BREEDING

The alpaca industry is ultimately a fleece industry and if we want to sustain it into the future we have to convince sceptical farmers that there is a financial return from alpacas. Without this the industry has a short lifespan in agriculture and will go the way of the pet industry. Livestock have to have some built in value beyond their cuteness and in this case it is an exquisite fleece that will have an increasing worldwide demand provided the fibre produced is of high quality. We have to breed consistency of conformation and fleece, eliminate micron blowouts, and reduce medullation or guard hair. Density of fleece and a finer micron can also be worked at but will come if we can improve the above three points. It is no good having an alpaca with a wonderful fleece and no frame or constitution to sustain it. Dead alpacas produce nothing. The reverse unless we are developing a meat industry, is also of no value to us, as alpacas that put protein into body fat instead of fleece are of little value. At this point we have to breed with all we have but ultimately eliminate those animals that don't measure up. The A.G.E ((Across Herd Genetic Evaluation Program) run by the AAA collects data on a range of traits (eg: fleece, micron) for evaluation. The data is analysed and the information is then passed back to the breeders to help them make the decision necessary to gain genetic improvement) system will help us do this but I would hope that every breeder has their own A.G.E program. There are other characteristics not yet covered by A.G.E that are also important, those being fertility, temperament, ability to forage and thrive, and early maturity (females breed at twelve months of age). In fact some aspects of our industry are holding us back, for example the continued showing of an alpaca retards its ability to forage and survive without supplementation, a characteristic we can ill afford to loose in our tough environment. The ability to cull successfully can only come about when you have alpacas of similar type; you can then eliminate those animals that lack the fleece and conformation characteristics you are looking for. Thus you need to breed with like animals and this industry has got to the point where it must look at line breeding to get this consistency as continual outcrossing makes it extremely difficult to move forward. For instance the genetics of some of our best animals can be eliminated in ten years with outcrossing, however with line breeding they can be retained to eternity. I am not talking about inbreeding. I am talking about line breeding with animals that combined have no more than fifty percent of one ancestor's blood.

LINE BREEDING

Line breeding is the system by which practically all lasting improvements in livestock have come about. To quote an American Hereford breeder J.H Lents who has written a practical book on line breeding (The Basis of Line Breeding, 1991) The ideal animal should possess those characteristics, which are economically important. These characteristics are structural correctness, soundness, longevity, fertility, and reproductive ability, uniformity, mothering ability, strength of constitution and efficiency of converting feed stuffs into the desired end product. J.H Lents should know as he has spent his life breeding Hereford cattle in a herd closed since 1881. His animals have been tested by vets for soundness and efficiency. They stand up against the best and do not display any deformities.

Line breeding is often put down as inbreeding but J.H Lents explanation is the best I have heard. He says Line breeding is a system of mating which concentrates the blood and influence of one or more ancestors to a level above that which would have existed had each of the ancestors names only appeared once in the pedigrees of their descendents. Line breeding never introduces more than fifty percent of the blood of any ancestor into a descendent regardless of the number of times the ancestors name may appear in the pedigree of that descendent.

In order for an animal to create positive change in their descendents that particular animal must possess three things, breeding, quality and individuality(Lents 1991).

To begin line breeding you must have in your minds eye the ideal animal you are looking for and animals of exceptional quality to breed to. It is no good just selecting any animal willy nilly. What makes the mind boggle about line breeding is the ability to produce an animal with forty percent plus blood of an ancestor that has been dead for fifty years. This is a way of protecting the qualities of outstanding individuals whose blood and influence would have been lost inside ten years with outcrossing. Another advantage of line breeding is that it tends to fix the undesirable characteristics lying dormant in the normal population and brings them to the fore enabling them to be identified and culled. With outcrossing these genetic defects are hidden and will appear in the future.

IN SUMMARY

We must look for alpacas that are adapting to Australian conditions i.e. those alpacas that are highly fertile, thrive and have the ability to maintain their body condition while raring a substantial cria and producing a quality fleece. Peru is a wonderful country but it has different climatic conditions to Australia, and just because an animal performs well in Peru it won’t necessarily perform the same here. Peru is a volcanic land. The soil is high in trace elements. Australia on the other hand is one of oldest countries in the world and many of the trace elements have been leached from the soil. Over the last few hundred years sheep and cattle have adapted to our harsh environment, while alpacas have been here just over fifteen years. Continually bringing in new imports and outcrossing makes the adaptation process more difficult. It is time we started to look at alpacas coming to Australia with a view to how they fit into our breeding programs. The areas alpacas are run in Peru are either very dry or the rains all come at the one time of the year. This enables the animals to carry more than twelve months (even up to four years) wool without damaging the fleece or causing any harm to the animal. The climate is not as hot and the altitude is much higher. If animals were run like that in Australia, we would find the fleeces would become weather damaged (rain, sun and humidity). The animals themselves would also suffer, getting waterlogged in winter and fly struck in summer and the constant heat could cause fertility problems, particularly in males (swollen testicles, low numbers of live sperm).

Many alpaca breeders throughout Australia have asked me whether they should be running alpacas in their area or should they move to a more suitable location. My answer is alpacas can be run in most of Australia except perhaps the tropics. It is a case of understanding the environment you live in and adapting alpacas to suit those conditions.

References:

* Blanmire, John. (2000). Science at a distance.

* Bailey, Regina. Your guide to Biology.

Lents, J.H., (1991). The Basis of Linebreeding.

Robbins, William. (2004). Evolving the Australian Alpaca.
AAA Conference 2004 Proceedings.

Vanderbeek, Fiona. (2004). An introduction to genetics applied to alpaca breeding. Southern Region NSW 2004 Alpaca Breeders Seminar.

* Wikipedia. The free encyclopedia.


* Denote from information sourced from the internet.

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