I'm embarrassed to say that I've grown foxtail millet in the garden for a few years and have never given it to the chickens. There are few different species of millet - foxtail, proso, and pearl are commonly used in birdseed. The spray millet you can buy at the pet shop is foxtail millet. Foxtail millet is very easy to grow and makes lovely Winter wreathes
Here's what Purdue U says about proso millet: "The feed value of proso has been studied with several classes of livestock. Luis et al. (1982a, b), investigated both broiler and turkey diets with proso. The turkey poults were significantly heavier at the end of the 28 day feeding period with proso than those on either corn or sorghum diets. Broilers fed balanced diets of the three cereals were not significantly different in gains. When proso was evaluated in layer diets it was concluded that "proso millet, either ground or whole, is an excellent ingredient for layer diets" (Luis et al. 1982c)."
I'm fairly sure that the researchers were not feeding proso to the chickens alone or to the exclusion of other cereal grains.
This year, I'll see what the chickens think of the millet.
* That's good news to me-- mine loves millet & I was a little worried it was too much chicken candy. . . She REALLY GOES BONKERS for the Milo though-- which is a sorghum seed I think. . . that they make molasses out of--???? It's that reddish orange seed/grain in bird mixes. . .