I agree with OtterSatin. Feed what you want, and those that don't do well will make themselves culls until the herd is stable. Each herd is a little different. What works for one person may not work for everyone. For instance, I will not feed any Purina products, but lots of people do and it's fine. Someone suggested that you should not feed TSC brand, but if I don't feed Purina, that's all there is left, so I've been feeding it for a month and no one has died. They blew their coats the first time, but there is a lower % of protein and not the best quality protein source, so I had to compensate for that.
I live in the city, there is no grain mill within 60 miles plus, so I'm stuck buying whatever is at TSC, the only feed store around. Sometimes you have to just choose and make do. Feed what your budget and conscience dictates (and hope they are the same thing).