bomen bos bospad herfst natuur Aberdeen angus agricultural agriculture Angus animal husbandry Australian beef black angus Bos taurus bovine breeders bulls bush cattle commercial cows farming fertile field fodder grass grazers graziers grazing herd hills livestock meat production paddock polled profitable reproductivity rural solid taurine cattle ungulates bevroren blaadjes cold forest Forrest frozen ice kou leafs vries vriezen winter animal-husbandry black-and-white breed calvers dairy dairy-breed dairy-cattle dairy-cows dehorned domesticated-ungulates graze green high-milk-yields Holstein-Friesian longevity milk-production milkers milking-cows pasture production quality ruminant ruminating versatile