... I know methionine is in kale, BOSS, flaxseed and broccoli so I can't see how I'm not meeting that amino acid requirement for them. I didn't mention flax in my feed recipe but, I started them on it last night. So far, the chicks have been eating everything I put out for them. The only thing they leave out is any bigger shell hulls from the BOSS that they can't eat.
Adult chickens need 1600 mg MET per pound of feed. Chicks need a higher percent.
Broccoli has 35 mg MET per 91 g
Kale has 18 g MET per 67 g
Sunflowers have 0.119 g MET per 28.35 g
Flaxseed has 10.5 mg MET per 28.35 g
so
34 g of broccoli has 13 mg of MET
34 g of kale has 9.13 mg of MET
152 g of sunflower seeds has 6.4 mg of MET
total of 28.5 from those three leaves 1571.5 mg to come from the flax seed which would take 4,455.2 g of flaxseed per day.
Source for the numbers I used for how much MET in Broccoli, Kale, Sunflowers, and Flax is
https://brendadavisrd.com/methionine-restricted-diet/
I think the source used hulled sunflowers and sunflowers eaten by people so most likely not BOSS but the numbers are so far off that it really doesn't matter much. The same for the fact that nutrient content and needs vary - they don't vary that much, especially upwards for protein.
Methionine is important in the development of the immune system and the gastrointestinal system. A small deficiency may not show up until the immune system is challenged (and then it may not be connected to diet during development).
An free ranging broody hen on a range that has adequate resources can show her chicks what to eat that provides what they need (possibly assuming she has had time to learn what to eat from her range). I don't know how successful chicks on their might be. It probably has a lot to do with how rich the environment is, how much time they have to forage, and how much drive they have to forage.
It would be good if someone else checked my math.