Reply #43: I think it depends on what you are doing.

[Scruffy1]

I grew up in agriculture. Started handling livestock when I was about 10. A bovine can seriously hurt you or even kill you. So can a horse or a hog. Knew one farmer who got eaten by his hogs. The most dangerous thing on a farm though is the machinery. I've seen people pinned under tipped over tractors, feet mangled in grain augers and grinders, hands caught in corn pickers and combines.
Then there are jobs like walking beans to pull weeds or planting trees, building fence, and cleaning chicken coops.
Yes, me and my best friend used to clean chicken coops on Saturdays to get enough dough to go out on Saturday night.
All in all I would say 16 years old is the minimum age for hired labor. There is plenty of life left after 16 to be a slave in.