Question

Why has animal rearing been developed on a large scale in the USA and Canada.​

Answer 1

Answer:

Meat Consumption and Livestock Production Trends And since the global population is itself growing, the world supports more domesticated food animals than they have historically. For these reasons, animal agriculture is growing globally, particularly in the production of pigs, sheep, goats and poultry in Asia.

*this is not an answer but it's a fact*