private void Button_Füttern(object sender, RoutedEventArgs e)
{
string heuMengeText = txtHeuMenge.Text;
double heuMenge = Convert.ToDouble(heuMengeText);
Kuh kuh = kuehe[currentKuh];
kuh.fressen(heuMenge);
setEigenschaftenKuh(currentKuh);
}
