Adding ractopamine to pig feed doesn’t make the pigs grow faster day by day, but it does help them turn food into muscle more efficiently and end up with leaner meat.

When pigs are fed a special additive called ractopamine, they eat about 10–15% less food over a month, but they still grow just as well—and they use the food they do eat more efficiently, like a smarter eater.

Adding a specific feed additive called ractopamine to pig food helps pigs grow more meat while eating less feed—especially in the last two weeks of the feeding period—and this works no matter how fat or skinny the pig was when they started.

When pigs are fed a special feed additive called ractopamine at a certain strength, they grow leaner muscle and less fat—especially after about a month—making their meat more muscle and less fatty.

Giving steers the same growth-promoting feed additive for two extra weeks—42 days instead of 28—doesn’t make them grow faster or change their meat quality in any meaningful way.