The US output of chicken meat has risen more than 20-fold since 1950, from 1.1 to 23.3 Mt in 2015, and the worldwide growth has been even more impressive, from less than 4 Mt in 1950 to just over 100 Mt in 2015 (FAO 2018). But this growth has subjected modern broilers to a great deal of stress, even to outright suffering.
Enough to go vegetarian
