Why Alcazar Suri Stud decided to keep the Suri pure

and not to cross with Huacaya

Genetic reasons

• A breed can only be developed by increasing the level of homozygous genes within its population. To maintain a breed is to make sure that all these genes remain homozygous. By crossing a strain (or a line) with another strain (or line), you increase the level of heterozygous genes. In other words, you increase the diversity, whereas the idea is to have animals as similar to each other as possible, including their progeny.
• When crossing Hereford cattle (red with a white head) with Angus cattle (all black, with no horns), you get black cattle with a white head and no horns called “black baldies”. Neither the Hereford Breed Society not the Angus Breed Society will ever accept these black baldies on their respective registries. They may all look similar to each other, but they are hybrids. The same can be said for suri x huacaya crosses. These first crosses between two pure breeds are called “F1’s” for first filial generation.
• What really proves that the F1 is not pure is what happens when you cross two F1’s together (to obtain F2’s). In the case of black baldies, you will obtain all red cattle, all black cattle, red cattle with a white head, black cattle with a white head, and all these cattle could be with or without horns. This is known as the second law of Mendel or independent segregation of characters. In other words, when crossing F1’s with F1’s you get all sorts of surprises. This is not what you expect within a pure breed. Purebred animals “breed true”. We do not have enough information about suri x huacaya F1’s to know what we can expect when crossing them together.
• Some breeders cross unrelated lines because they expect to obtain hybrid vigor. It is true that F1’s exhibit hybrid vigor. However, if breeding for hybrid vigor is your aim, you should make sure that the F1’s are your “finished product”. This is because 50% of the hybrid vigor is lost in F2’s. F1’s make ideal commercial animals. In the case of alpacas, F1’s may be ideal fleece producing animals but they would not be very good as quality reproducers (i.e. consistent, prepotent, breeding true).
• Some breeders have decided to cross suri and huacaya in an attempt to import huacaya colour genes into the suri population or suri lustre genes into the huacaya population. This may appear as a good idea. However, the price to pay may be high for the suri breed. In effect the suri is suspected to be stronger and more robust than the huacaya ⁶ and to live longer ²; its fleece is much more lustrous, exhibits a low degree of medullation ⁶ and grows 1 to 2 cm longer in a given year.² Will all these commercially important characters be maintained in hybrids? What we know about such characters in other species, especially sheep, suggests that they are governed by polygenes and are therefore inherited in a quantitative additive manner: This suggests that they would be halved in hybrids.

Marketing and commercial reasons

• The Suri is being promoted and marketed as a unique animal producing an exclusive luxurious fibre. The animals are still rare and therefore this explains high prices paid, by comparison with huacayas.
• It is not logical to promote the suri this way and, at the same time, “bastardising” them by crossing with huacaya. The message sent to the public is confusing.
• The public will soon be more educated and understand the difference between pureblooded suris and hybrids. Prices paid for pure stock are already higher than what is paid for crosses.

Historical reasons

Some prominent suri breeders all over the world have made clear comments about the risks associated with crossing suri and huacaya:

• Don Julio Barreda (Peru) wrote, “we should all consider the Suri an endangered species. It is said that there are two ways to extinguish a species: (a) with bullets, and (b) by mixed-breeding. […] I have been full of wonder, asking myself how long it will be before the Suri stops existing as a genuine breed, a unique prototype of the American Camelid.”²

• Dr Cheryl Tillman, Veterinarian, and husband Andy (USA) state that they “do not want to sacrifice suri character or purity for colour. […] We have a responsibility to preserve the genetic purity of the suri. We do not cross-breed huacayas and suris.”³

• Dr Phillip Sponenberg (Veterinarian, PhD, Professor of Pathology & Genetics at the Virginia-Maryland Regional College of Veterinary Medicine and accessorily a hand spinner) asks: “How important is the single gene to the production of first-rate suri, and how important are all the other genes which are probably only expressed on suris? [Crossing of suri to huacaya would] merely disrupt the host of modifiers needed to produce an excellent suri. If this is true, then the routine crossing of the two types in an attempt to produce more suris is probably shortsighted since the overall quality may not be there.”⁵

• Andrew and Karen Caldwell, respectively AAA Foundation Judge and AAA Committee Member (Australia), ask: “Why is it that, in Peru, Chile and Bolivia, they continuously educate and encourage their farmers to strive diligently to keep [suri and huacaya] pure and separate? […] We believe that hybrid animals produced from the practice of crossing suri and huacaya should never appear in a purebred registry for any reason. Whether they look like one strain or the other, they are, genetically, a cross between two strains.”⁴

• Wendy Billington (Australia) states, “the first cross [between suri and huacaya] does not always deliver the lustre, staple length or lock architecture of the true Suri.”¹

• Dr Paul Carney (Australia) argues that “since the suris were a rare group of animals, it is possible that other genetic attributes locked up in that group will make a significant difference in ways other than the straight forward suri/huacaya difference [and that] there may, for example, be some genes for fineness and lustre restricted to the suri group.”¹

References

1. SAFLEY M. - The suri gene supreme: A crossbreeding conundrum – Alpacas, pp 58-68, 1999

2. BARREDA J. – Let’s save the Suri – Alpaca International News, pp 7-12, 1994

3. TILLMAN C. and TILLMAN A. – A pasture full of light bulbs – Alpacas Magazine, pp 62-63, Summer 2000

4. CALDWELL A. and CALDWELL K. – Huacaya x Suri – Alpacas Australia, No 14, pp 39-40, 1996

5. SPONENBERG P. – Jiggling genes – http://www.teleport.com/~nwa/genetics.html

6. BILLINGTON W. – personal communication; Suri Education Day – Cedar House Alpaca Stud, Yass, 16^th July 2000

Pierre Baychelier

October 2000