Recipient herd
Selecting your recipient
At PVH we have a vast array of high quality cattle available for all your embryo recipient needs. All cattle have been carefully selected to be a part of this top quality herd.
When selecting a recipient female to transfer any of your high quality embryos into it is important to take in a few considerations. Cows that are reproductively sound, exhibit calving ease and have good milking and mothering ability are premium recipient prospects. They must be on a proper plane of nutrition (body condition score 6 for beef cows and dairy body condition score 3 to 4). These cows also must be on a sound herd health program.
synchronizing your recipient
To maximize embryo survival in the recipient female following transfer, conditions in the recipient reproductive tract should closely resemble those in the donor. This requires synchronization of the estrous cycles between the donor and the recipients, optimally within one day of each other. Synchronization of the recipients can be done in a similar manner and at the same working time as the donor cows. There are a number of different estrous synchronization protocols with advantages and disadvantages for each protocol. The critical point regarding recipient cow estrous synchronization is the timing must match the time of insemination of the donor cow so that the donor and the recipients have a similar uterine environment seven days later when the transfer takes place. Synchronizing products are more effective on recipient females that are already cycling. “Anestrus” or noncycling cows that are too thin or too short in days postpartum will not make useful recipients.
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How often can oocytes be collected?Oocytes can be collected every two weeks and this is one of the main advantages of IVF as cows can be collected more rapidly to improve genetic genes.
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What results can be expected with each IVF?An average mature breed cow will give 18 oocytes which should translate into roughly 5 freezable quality embryos. Beef heifers will vary more in their oocyte numbers and embryo development rates. However, typically we will see 30-40% of oocytes develop into freezable quality embryos.
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What donor females make good candidates for IVF?Similar to conventional embryo production highly fertile cows will still produce better in an IVF scenario. Donor selection criteria such as age, parity, fertile history and nutritional status are essential in choosing proper candidates for IVF. However, cow that do not perform well in a conventional flush should still perform well in an IVF.
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How young can heifers be IVF'd?Heifers can be collected as early as 8 months, but for best results it is common to wait until they’ve had their own natural heat cycle prior to collection.
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What are grade 2 IVF embryos?According to IETS grading standards a Grade 2 IVF embryo would have a similar classification to a Grade 1 (excellent) conventional embryo. Pregnancy rates between Grade 1 and Grade 2 IVF embryo are very similar.