1. Which country has the highest efficiency (grass to milk)?

The Netherlands produce more milk per ha. This is partly because of the relief of Slovenia and partly because of the inefficient way the hectares are separated in Slovenia. Most farmers have land on lots of different locations. In the Netherlands this is also a small problem, but it's better than in Slovenia. Slovenian cows are also less efficient in producing milk because they're also used for producing meat, in contrary to the Netherlands, where dairy cows are only used for milk.