It is not a cow.
Couple of points.
First, yes this animal is big, but there are a couple of reasons for that.
In the EU rules on slaughter of older animals due to risks they have from passing mad cow disease on means it would be worth much less.
And in the pics I have seen, he seems to be in a herd of very young cattle..
If more farmers kept their Holstein bullocks for 7 years, this would be a much more common sight