When you guys use a dual purpose bird for meat, do you feed them a "broiler" diet or a "layer" diet? I hope to raise at least some of my NN Turkens for meat and I'm not sure if I should feed them differently from my egg layers.
Everyone has different preferences for different reasons.
Buy feed for the purpose. Layer feed is for layers. Pick a brand and follow the directions on the bag. They are each mixed for the purpose. Some better than others.
As was mentioned Flockraiser is a good all round feed for growing and adult birds.