The greatest worry in chicken is antibiotic use, not hormones.
In 1957 the average growth period for an eating chicken to reach slaughter weight was 63 days. By the 1990s the number of growth days had been reduced to 38 and the amount of feed required halved.
This is through selective breeding, not injection of hormones which in the Chicken industry is illegal and also impractical (injecting chickens one by one with bio-identical or synthetic hormones at least three times daily)
This means chickens are large on top and their legs buckle with the impossible weight.
As.a result, they wade in their feces alot of the time and in large and cramped "free roaming" communal barns are vulnerable to the deadly cambylobacter, requiring antibiotics.
Antibiotics use in poultry has been linked to antibiotic resistance in humans.
Antibiotic-free chicken too expensive?
For Philip Lymbery, chief executive of Compassion in World Farming, the argument that intensive farming is justified because poorer people need cheap meat or eggs is insulting to those on lower incomes.
An intensively reared chicken is three times higher in fat, one third lower in protein, and lower in beneficial omega-3 fatty acids now than it was in the 1970s.