Increasing the number of Quality Purebred Persians in Australia.
All Persian sheep in Australia are descended from 3 small consignments of embryos that were imported into Australia from South Africa in the last 20 years. One shipment was imported in 1999 and two in 2006. One of the big issues at the moment, as indeed with any rare breed is “How do we get more of them – in particular females?” Not all breeders agree as to what method is best. Indeed the issue is quite contentious in some circles. Essentially there are 3 ways of producing purebred lambs.
Naturally Here purebred ewes are mated to the best ram available. Ewes give birth usually in their second year of life after a 152 day gestation . Persian ewes can be expected to lamb each year up to about 6 years of age and less reliably after that. On average about every third gestation produces twins. Using these figures each ewe would on average produce 6 – 7 lambs before 6 years of age. As just under half of all lambs born are ewes statistically 3 of these are likely to be ewes.
Upgrading In this process pure Persian rams are crossed to sheep of other breeds, usually Dorpers to produce hybrids. After 5 generations some believe that the resultant sheep produced, which by this stage contain on average about 97% Persian genes could be classed as purebreds. The main disadvantages of this system are that it takes years, is costly and produces a large number of essentially unwanted crossbred animals. Essentially it works like this. 1/Ewes, usually Dorpers are chosen to mate to a Persian ram. As Dorpers are approximately half Persian they represent the first cross ( or F1 Persian hybrids ) 2/ If 20 Dorper ewes ( for example ) are mated to a Persian ram. On average this is likely to produce 10 ewe lambs ( that are second cross ie F2 Persian hybrids) and 10 ram lambs. The 10 ram lambs are discarded from the breeding program 3/ The 10 second cross ( F2 ) ewe lambs are then mated to another Persian ram. On average this is likely to produce 5 ewe lambs and 5 ram lambs. The 5 ram lambs are discarded from the breeding program 4/ The 5 third cross ( or F3 ) ewe lambs are then mated to another Persian ram. On average this produces 2-3 ewe lambs and 2-3 ram lambs. The ram lambs are discarded from the breeding program 5/ The 2- 3 fourth cross ( or F4 ) ewe lambs are mated to a Persian ram . On average this produces 1 or 2 ewe lambs and 1or 2 ram lambs. The ram lambs are again discarded from the breeding program. 6/ The 1 or 2 fifth cross (or F5) ewe lambs are submitted for assessment and may be considered for registration as a Persian sheep. The ram lambs are discarded from the breeding program If each ewe lamb is mated to produce a lamb at around her first birthday ( which is probably optimistic ) the time involved to produce the 1 or 2 F5 ewes is 4 years.
The principle costs involved are a/ purchase of 20 Dorper ewes – for a sound, well structured 3 to 4 year old ewe in good health from a recognised breeder = $ 2000, b/ purchase of Persian rams -- 3 or 4 ( ideally ) would be required, these would need to be of a reasonable quality otherwise the entire breeding program would be a waste of time. $500 each approximately = $1500 to $2000 c/ cost of feeding , general care , worming , vaccination of all sheep involved—very hard to quantify but over 4 years $2000 would be extremely conservative to produce the 40 lambs involved and care for the mothers.
What happens to the crossbreds produced? Upgrading produces large numbers of crossbred animals and very low numbers of “purebreds”. In the example above, statistically 18 to 20 crossbred rams would be produced. 18 to 20 crossbred ewes would be produced. 1 to 2 97% pure Persian ewes are produced and 1 to 2, 97% pure Persian rams are produced. The sale of crossbreds could offset costs but how should they be sold. There is no shortage of mixed bred sheep being sold through outlets such as Gumtree often to vulnerable purchasers thinking they are buying purebreds. Because Persians are small sheep if they were sent to slaughter the return is low- perhaps $50 / head. The deliberate production of large numbers of crossbreds and what should happen to them is indeed problematic
Another potential disadvantage is that gene sharing is not always even. If a registered Persian ram is crossed with a ewe of another breed, the lambs are not all 50% Persian. This is the average amount of gene sharing and is the level found actually in only 1% of lambs. In reality the lambs are anywhere between 1% and 99% Persian. When you get to F5, the lambs in theory could be anywhere from 5% to 95% Persian. Many of these F5 crossbred animals will look like Persians but as many genes are carried recessively they will not be visible phenotypically. These recessive genes will become apparent as these animals are bred from, particularly if these animals are mated together.
Based on the above figures the 2 or 3 Persians produced would cost $ 5,500 to $6,000 to produce. Statistically half would be ewes. For this cost only one F5 ewe may be produced .This of course makes no allowance for the breeder’s time and ignores unpredictable problems such as the death of a ewe or lamb. This cost does however have the potential to be offset by the sale of the 1 or 2 F5 rams produced, resale of the Dorper ewes, resale of the purchased Persian rams and disposal of the crossbreds ( by whatever method the breeder chose).
Embryo Transfer (ET) In this technique ewes are given hormones to initially stimulate follicles to form on their ovaries and then later for these follicles to release their eggs. After insemination the ewes are anaesthetised and in an operation that lasts about 5 minutes and involves making a 3cm incision in the abdomen the resultant embryos are flushed from the uterus and collected. The embryos are then placed into recipient ewes under anaesthetic which have been hormonally synchronized with the donor ewes. This procedure takes about 5 minutes also and is done through a keyhole incision. The recipient ewes then carry the embryo / foetus / lamb to term , give birth naturally and raise the lamb as their own. On average 6 lambs are obtained with each flush but more can be obtained. Occasionally over 40 can be obtained. It is unusual to get less than 3.After flushing the donor ewes can be returned to the paddock, run normally with a ram and give birth to their own lamb naturally. The technique in sheep employs the same technology and methods used in IVF in people.
The obvious advantage of ET is that large numbers of absolutely pure Persians are produced quickly. On average 6 lambs can produced from one ewe in 5 months. With natural breeding this would take at least 5 years. Cost is a factor. If 6 lambs are produced each lamb costs approximately $400 ie $2,400 for 6 purebred Persians. Statistically half will be rams and half ewes. If the aim is to produce ewes and the rams are not required in effect each ewe will cost $800 although the purebred rams will have a value and can be made available for sale to offset costs.
As to what method is best is extremely contentious at the moment between various breeders. The Persian Sheep Breeders Australia ( PSBA) is a face book page operated by Janelle Cooper. The PSBA strongly supports upgrading as the preferred method. The site is heavily censored and any post that does not agree with Janelle’s view is quickly removed. Janelle is president of a group of Persian sheep enthusiasts called the Persian Sheep Society of Australia. She is very enthusiastic about Persians and has definite views about various aspects of their management. In particular she holds strong views about the various methods available to increase the numbers of Persian ewes in Australia. She maintains a flock of 16 pure ewes herself ( March 2019 , pers com ) and lives in NW Victoria. The PSBA site advertises her sheep for sale as well as those of some of her friends. She posted on her PSBA facebook page on the 25 April 2019 “Big shout out to all the Persian owners and breeders out there who are patiently and slowly grading up their Persian flocks by using a pure ram over graded ewes. That is how the average person builds up their flock when numbers are so limited. There is no need to put your ewes through expensive painful vet procedures just to boost your "hobby" flock numbers as some breeders do. Its cruel and only serves to boost the breeders ego as then they can boast to have more Persians than everyone else. Quality not quantity people. Take your time choose your best stock and go from there. Persians are a beautiful gentle breed and should be cherished not used as breeding machines”
It is important that breeders remember that this site is filtered. There were a number of comments that did not agree with this point of view. All were deleted. Often on the internet personal opinion is presented as fact and is not backed by any evidence.
My response on behalf of the Australian Persian Sheep Association to this post was deleted by Janelle. It is repeated below in point form with some changes for clarity. 1/ I believe that if breeders do want to accelerate the production of pure animals that it is better to encourage owners to increase numbers through superovulation and embryo transfer or at least discuss this method as an option. This method is cheaper, quicker and produces larger number of absolute pure Persians . There is no gene pollution.
2/ Embryo Transfer is a standard veterinary practice that is not regarded as cruel by the RSPCA or the Australian Veterinary Association. The PSSA opinion is therefore at odds with the belief of these respected organizations. It is important to remember that embryo transfer in sheep and IVF in people use the same methods and techniques. Obviously IVF is not regarded as “cruel” in people. It is important to remember also that if not for ET there would be no Persian sheep in Australia. This is the way the breed was introduced into this country. Does this mean the PSSA supports this practice which is stated as being cruel under some circumstances but not others.
3/There are at least 400 purebred Persian ewes in Australia now that have not been produced by crossbreeding . This puts Persians into the endangered category (according to the Rare Breeds Trust ). Does this still mean they are a rare breed? I am very worried about substandard animals being classed as Persians particularly if 2 of these can be mated and the lambs are also classed as Persians. I have seen F5 sheep that are obviously not Persians. It is usually the tail set that gives them away. Is there still a need to upgrade from Dorpers or others now? I would think probably not. I feel this practice will just downgrade the standing of Australian Persians in the rest of the world.
4/ What is the fate of all the crossbred sheep produced in the process of producing the small number of purebreds through crossbreeding? Looking at Gumtree it seems that many are passed off as purebreds to vulnerable buyers. Are others slaughtered? I am really having trouble seeing how this is a preferred method over ET that produces a smaller number of valued absolute purebred animals. The statement “ Quality not quantity” makes no sense when talking about upgrading . Exactly the opposite is achieved. 5/Australia is in a unique situation. We are totally free of all the vesicular diseases such as foot and mouth disease and as such are therefore an attractive market to other breeders around the world. In some countries we are the only source country available to breeders. Import is allowed from Australia but not from South Africa, other African or Middle Eastern countries. It is important that the quality of the Australian flock is maintained. I feel that recommending crossbred programs put this at risk