Feather meal is a common additive in fertilizers. It has an NPK of 12-0-0. I bought some a few months ago when I couldn't get blood meal, but don't have any results to report because this has been a weird gardening year. I did use it on my basil, which has been bountiful, but I can't isolate the reason for that. Sure wasn't the scorching weather!
According to some studies, feather meal effectiveness at providing nitrogen manifests only after it is completely decomposed.