Scanned a herd of dairy cows outside Ardmayle, Cashel, Co.Tipperary. Two cows, a mother and daughter, we scanned pregnant to the surprise of the owner in question. These animals had previously shown heats while pregnant. They were persumed empty and were for culling by the owner.
Up to 10% of pregnant cows may show heat while pregnant. I have previously seen it, as a trait in family lines of breeding.
Dr Dan @ www.cows365.ie