Buttercups and cows

We have three young cows in the buttercup field. I still have not got an answer to the question as to whether cows eat buttercups. At the moment I can only find out that they are not poisonous, but can make them a little ill, so they avoid them, unless there is nothing else. I presume therefore that the fact that the buttercups disappear when cows have been in the field is more to do with them being trampled than with their being eaten. I may be wrong. 

Windy today, cold and showery. We had our boiler serviced and it is still going fine after many, many years.