Sarah, I have always used a commercial feed of some sort as a base and mainstay for the birds. But I often sweeten the feed for the breeders and any special birds that I am keeping separated. The basic feed hopefully keeps the nutrient level close to where it should be and the extras hopefully make it better. That is unless you give them so much extra that you dilute the nutrients/protein in the "balanced ration". There are many products that folks have talked about using on many posts in the past. Sunflower seed, oats, cat food, various oils, fish/meat scrapes, and just about anything to give them extra protein will help with breeding. Some breeders or exhibitors will keep them on a weekly supplement of vitamins, Red cell, calf manna or so many other things come to mind. (I did a search for feed and found 'too many posts to link' over the years. It's not a scientific approach by any means, but at least it makes the breeder feel like they are helping somewhat. And if you hand feed them, it helps train them to look for a treat when someone approaches their cage. So I would take your basic feed recipe and add some of the things that you find in the posts, see what works best and let us know if you feel like you've found a magic formula.