BREEDING YOUR FRIESIAN ( Aust. & NZ )

EMBRYO TRANSFER

ET (embryo transfer or embryo transplant as it is sometimes called) is another useful tool available to breeders today. Whilst some Studbooks do not allow the use of ET, the FPS are very progressive in this area and currently allow the registration of up to five (5) foals from the one dam in the one breeding season. There are some basic requirements such as you must notify the FPS through the ANZFHS prior to commencing the breeding program and provided you are using Studbook Stallions and a mare of sufficient quality it is likely you would be given permission to proceed. The ANZFHS also have a number of conditions that must be met such as minimum height etc and this can be confirmed by contacting the Secretary of the ANZFHS. Verbal approval may come from the ANZFHS though rejection of an application would have to come from the FPS. It would be wise to obtain 'written' approval and should your application be rejected you should request this rejection in writing from the FPS. The FPS recommend (this is a recommendation not a requirement) that Friesian mares are used as the recipients in an ET program and whilst this would be ideal from a foal rearing point of view it is not always possible in Australia or New Zealand given the low number of purebred Friesian mares. You should also be prepared for a DNA test on each ET foal to confirm parentage as this would generally be required by the FPS prior to registration of the foal. Friesian foals are not excessively large in relation to foals of other breeds therefore apart from the FPS preference for a Friesian mare to suckle and raise the foal ( the theory being that a Friesian makes the best mother for a Friesian foal) there does not appear to be any physical reason why a normal healthy mare of around 15.5 to 16HH cannot carry an ET pregnancy to term and deliver a healthy Friesian foal. 

The ET process starts with an AI procedure though the degree of difficulty is significantly higher than with normal AI and the experience and ability of the vet is paramount to a successful outcome. 

When selecting a vet for an ET  breeding you really should only use someone who has a proven record of success. Just because your vet has a record of success with AI  does not necessarily mean that they have experience with ET, this is very much a specialist's field.

As with AI, selection of the stallion and arranging straws  has to be done early as does selection of the vet. ET requires the participation of more than one mare so take this into consideration. Just about all experienced ET vets would have their own herd of mares kept specifically for ET programs. Use these mares rather than your own mares as your vet would have chosen his ET mares carefully and will know them intimately. Working with a known quantity is far more beneficial than with an un-known quantity and presents far fewer surprises that may adversely effect the program. 

Each vet will have a different system but a basic system used by some  vets may go something like this:

• Two Recipient mares would be selected  for each attempted ET. 

Reason - they have to match the recipient mares cycle to that of your mare and what would happen if the recipient mare decided to come down with a virus or injure herself a few days before the ET was to take place. Answer - no ET but you still have a big vet bill because you have already done the AI and all the lead-up work for the ET. This also means you quite possible will have to forget about the ET for this season. Whilst selecting two recipient mares does cost you a little more in 'agistment/up-keep' it is actually a safety net for you, not a revenue gaining exercise for the vet.

• You will be asked to pay an 'up-keep' fee on each recipient mare whilst she is part of your breeding program. Something like an agistment fee.

Reason - your vet has bought and maintained these mares specifically for this type of work and they have to recoup some of these expenses. This fee is likely to start from the day the recipient mares are scheduled into the program.

• You may then be asked if you want to lease or buy the recipient mare that will be carrying your ET foal.

Reason - once you have a successful ET and the recipient mare is pregnant you will need to take her home and care for her. She belongs to your vet at this point so you must either lease her until the foal is weaned or buy her from the vet. Buying may prove to be more economical but either way it is not a huge expense. Most vets would charge from $500-800.00 for either the lease or a straight sale. Compared with the cost of you providing your own recipient mare and the risks associated with that as outlined earlier, this is not an expensive option. Remember, you only lease or buy the mare carrying your foal, not both mares in the program.  

• You will then need to transport  your mare to your vet's Breeding Clinic for the initial AI ( refer to AI for what this entails with regard to preplanning etc) and also arrange for the transport of your straws from where ever you have them stored.

Reason - AI and ET cannot really be performed effectively 'on farm' unless you have a resident vet experienced in this type of work and I imagine very few or us would be lucky enough to employ our own vet, living on the premises.

• Your vet will then co-ordinate the cycles of all three mares so that when the embryo is ready to be collected from your mare, both of the recipient mares are ready to accept it. 

• Then your mare is monitored and when ready the AI process is performed.

• Around 7 to 8 days after the AI, your mare is flushed and hopefully a viable embryo is captured.

Note - The embryo has to be retrieved from your mare at around 7 days of age so that it has a reasonable chance of survival. Embryos collected at day 6 or day 9 have a much lower viability so this is a critical date. Embryos are quite pliable at this age and become significantly more 'fragile' as they get older. This presents the first challenge for the ET breeder as it is virtually impossible to confirm the embryo even exists at 7 to 8 days of age and leaving it longer (which would enable confirmation by scanning) means that you may be able to confirm the AI has been successful but you have also virtually guaranteed that your ET will not be successful as an embryo beyond 10 days of age will almost always be too fragile to flush and transplant into the recipient. What all this means is that your vet will be flushing your mare and 'hoping' that they have a viable embryo and that they have captured it. The next step is for your vet to filter the flushing fluid and search for an embryo that will be almost impossible to see with the naked eye. At this age embryos are well under one millimetre in diameter. If the AI has been successful and the flush has recovered ALL material from the uterus and your vet has collected a healthy embryo you have passed a significant hurdle.

• The next step is for your vet to implant the embryo in the recipient mare. Your mare would then be checked over to make sure she is clean and healthy and if you intend to also allow your mare to carry a foal this season she would remain at the clinic to go through the AI process again when she comes back into season or is 'brought on' buy the vet.

• Once the embryo has been implanted the recipient mare would be monitored as in a normal breeding.

The cost of an ET breeding will vary from vet to vet and is also dependant on the degree of difficulty in achieving the pregnancy. You would be wise to consult your vet about cost BEFORE you start the program. 

These are the  basics steps that you will need to be aware of so that you have some understanding of what  your mare, your vet and the recipient mare  will go through to give you an ET  foal. I have not mentioned all the late nights monitoring the mares or the need for certain drugs to make sure everything goes smoothly or numerous other steps your vet and their assistants need to go through on your behalf. Suffice to say, it is not for the faint hearted and not to be entered into lightly. In every step along the path to success there are pitfalls that have the potential to end your ET program. The work load and expense for your vet will not  significantly differ whether the end result is success or failure and this should be considered prior to starting. Whilst the opportunity for failure is quite high compared to a normal AI, the choice of vet and your ability to work closely with your vet will greatly enhance your chances of success. There is also another point to consider; whether or not your choice of stallion and mare have the ability to give  you a foal you consider worthy of all this effort and expense. That is a question only you can answer.

For all those attempting an ET breeding, good luck and thank you for pushing just that little bit harder for the future of the Friesian in Australia and New Zealand.