Bilal Butt knows how it sounds. The associate professor of sustainability and development at the University of Michigan understands that arguing to let cattle graze in a national park offends the sensibilities. Bilal Butt knows how it sounds. The associate professor of sustainability and development at the University of Michigan understands that arguing to let cattle graze in a national park offends the sensibilities. Plants & Animals Ecology Phys.org – latest science and technology news stories