Artificial insemination embryo storage containersTwo sheep embryos having been artifically inseminatedA ewe and five lambs in a field

Innovis embryo freezing and storage


Freezing embryos from your elite females enables sheep breeders to preserve your best genetics and Innovis’ embryo freezing and storage facilities enable breeders from across the UK to take advantage of this.


In season and out of season flushing and freezing

Innovis is the UK’s leading provider of embryo freezing services for sheep and we offer breeders the opportunity to freeze embryos both in season and out of season. We have successfully superovulated and flushed ewes outside of the main breeding season and these embryos are frozen for implanting in the next breeding season. This also enables valuable ewes to be flushed repeatedly throughout the year. Ewes found barren at scanning can also be flushed to collect embryos which are frozen for transfer in the next breeding season.


Approved facilities

Breeders can access our dedicated facilities in England, Scotland, Wales and Northern Ireland. Most international movement of livestock genetics now occurs in the form of frozen embryos and Innovis has DEFRA approved, quarantine facilities in Malvern and Edinburgh which enable breeders to export embryos worldwide.


For more information about our embryo transfer (ET) services for sheep, please see our sheep embryo transfer services page.


Ask our Innovis technical team about embryo freezing


What does embryo freezing involve?

For embryo flushing and freezing the donor ewe is super-ovulated using hormones so that she produces more eggs than usual at a synchronised mating. This programme usually lasts 20 days with the ewe being artificially inseminated (AI ) on day 14 and the six-day-old fertilised embryos being “flushed” from her on day 20. Embryos are then frozen or cryp-preserved for future use. The flushing process is performed under general anaesthetic and will take approximately 30 minutes per ewe. Embryos are then checked, placed in a special freezing medium and chilled slowly ready for storage.


How many embryos will a ewe produce?

Although it varies greatly, on average about 7 embryos are collected per superovulated flush from a ewe during the breeding season.


Will a ewe always produce embryos suitable for freezing?

Not all sheep embryos will be suitable for freezing. Embryos are graded against a standard and only grade 1 and 2 embryos are frozen. The quality of the embryos is always checked again post-thawing.


How are frozen embryos stored?

Sheep embryos are generally frozen in plastic straws, with each straw containing 2-4 embryos of a similar developmental stage from the same flush. Embryos are stored in tanks of liquid nitrogen which keeps the embryos frozen at a temperature of around −196 °C or −321 °F.


I want to have embryos frozen for export, what must I do?

Innovis has dedicated teams who have expertise in the import and export of frozen embryos. Special quarantine requirements exist for different countries. Please ask us for more information about this service.


How much does embryo freezing cost?

Current embryo freezing costs can be found in our price list. At Innovis we share the risk with you when implanting frozen embryos – contact your nearest centre to discuss what we can offer you. Terms and conditions of Sale apply.


More information

We also have a full range of information, technical factsheets and support available for sheep breeders who want to take advantage of our services and expertise


  • Ram preparation Guidelines
  • Laparoscopic insemination in Sheep
  • Checklist for AI / ET – the ideal set up
  • Getting your ewes into shape for AI
  • Improving Lap AI and ET conception rates
  • Why use a teaser or vasectomised ram in your flock?
  • Regulin – its use in AI programmes


Do you want further information about semen freezing?

Please contact your nearest Centre: Malvern on 0844 800 9050 or Edinburgh/Belfast on 01875 614500

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