With calves weaned, veterinarians criss-cross the country conducting pregnancy checks, or preg checking, cow herds. The vet calls out and marks an “O” on the hips of “open” or non-pregnant cows.

With calves weaned, veterinarians cross the country conducting pregnancy checks, or preg checking, cow herds. The vet calls ...

In experiments on mice, even at concentrations 100 times higher than milk from pregnant cows, blood hormone levels and reproductive organs were unaffected by dietary estrogens, report investigators in ...