The breeding scheme entails yield differences of more than 2 000 kg energy corrected milk (ECM) per cow and year. On average, farms feeding less concentrate yielded slightly lower milk yields per cow and year, however, because of the longer productive life the cows showed similar milk yields over their lifetime. The farms investigated so far appeared to have healthy cows, even if fed low levels of concentrates or in the case of extremely low or high urea contents in the milk. These values could indicate the cows’ ability to compensate for short-dated changes
