Cows deliver healthy calves without embryonic protein long thought essential for pregnancy

Cows deliver healthy calves without embryonic protein long thought essential for pregnancy. For decades, scientists have believed that a protein called interferon tau (IFNT) is indispensable for pregnancy in cattle. Produced by the early embryo, it was thought to signal its presence to the mother and prevent the hormonal changes that would otherwise end the pregnancy. A new study challenges this long-held belief.