Frozen little piggies

摘要

Pig embryos can now be chilled and stored, and then successfully implanted into sows. Farmers have been using a similar technique with cattle for more than a decade, but until now it has not worked well with pigs. Five piglets due to be born this week at the US Department of Agriculture research centre in Beltsville, Maryland, will be the third litter from the technique. Cattle embryos have been frozen routinely since the mid-1980s. Breeders can store thousands of frozen embryos for years and ship them quickly and cheaply to farmers, who can implant them into their own cows.