Yeah, I had mixed up the numbers... All my chickens free feed, and the last time I had been looking at feed amounts it was because a teenaged pullet had sour crop.
Supposedly at about 6 weeks they eat 1.5 oz/per day... According to the google search I just did, because you posed an interesting...
I will feed them hard boiled egg yolk. Maybe some lettuce or spinach (starting at 2-3 weeks, ay earliest), but then I make sure I have some grit for them too. The grit won't hurt them (and I literally use sand from my yard).
I also like to make sure they're socialized, as when they get older...