It is feed lot animals that are the concern . pasture raised in the sunshine farmed animals are fine. Type 2 Diabetic Grain fed animals ? are not.
I wonder how many Kangaroo and Emu were running around in Australia in 1788 !
And what did we do ?
Motorway
Found this -->
'The numbers of kangaroos present in Australia at the time of first European settlement can be estimated on the basis on the number of introduced herbivores supported on unimproved pasture and browse. The population was probably of the order of one to two hundred million' . Auty J, (2005), 'Red Plague Grey Plague, Kangaroo Myths and Legends,' In 'Kangaroo Myths and Realities,' (Australian Wildlife Protection Council, Melbourne, Vic) p.62
And that land supported myriad numbers of other living organisms. From the smallest ( eg Bacteria ) to the largest.
200 mil ! How many Emus too I wonder.
Motorway