This was a hard slab of salted, minced and sometimes smoked beef mixed with onions and breadcrumbs.

NPR: Building a Better Burger

Pink slime occurs when sub-par beef scraps and connective tissue are mixed with ammonia to turn formerly inedible meat into edible ground beef.

FORBES: Let's Get Naked: A Guide to Brand Transparency

Investigations have begun in Poland to find out how beef and horse products were mixed.

BBC: Horsemeat row: Trade union's fears over Silvercrest jobs

It is a mixed farm, with arable crops and a 40-strong herd of beef cattle.

BBC: The farmer's tale