Ok, heres the only hatchery that has a site.
http://www.pkgills.com/
Pk gills

I also have bought feed in anticipation of feeding them.
40-60% predation? how fast are we talking about? What birds and what kind of animals hunt trout?

"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery."
Winston Churchill