That protein percentage is pretty good. Some I have seen over 30%, so I think the 21% is probably o.k. I would just not mix the corn/scratch with the feed, scatter a small amount for them as a treat instead.Alright on the label it says.
Crude Protein 21.50%
Crude fat 4.00%
Crude fiber 4.00%
Ash 8.50%
Then it has all the ingrediants. I didnt state all the vitamins and nutrients, so maybe the feed might be the problem?
Generally they are outside, but there isn't much outside except dry dirt, so maybe it could be stress issue? I'll stop mixing the feed, but what feed should I change to if that is the case. I will seperate the roosters. As far as the roosters mounting each other I have not seen them do it, but one family member has joked and commented that the roosters have mounted each other. I will stay vigilant on that.
Having a bare run, they may be bored as well. Do they dust bath?
You can try adding some perches for them to get on, add some pine needles/leaves or straw to the run for them to scratch in. For a treat, a small amount of greens or a cabbage hung up for them to pick at. Google "boredom busters for chickens" to find more creative ideas.
Personally, I do like higher protein feed (18-20%). I use Purina Flock Raiser and provide oyster shell free choice for my layers. I try to limit treats to no more than 5-10% of daily intake. My treats can be anything from a little scratch/shelled sunflower seeds, fruit/veggies to eggs. One thing I don't give is bread.