I mix my own seed and have done for several years now, there are a number of advantages to this, the first being when mixing your own you know what your getting in relation to content. The second being that if you purchase plain seed i.e. panicum millet, white millet, plain canary etc, then there’s no vat on your purchases resulting in more seed for your money. The down side is that you have to mix it, but if you purchase suitable containers you can mix your seed to your own requirements as and when you need it. There's also a further advantage "Cost Savings" and in this day and age the more you can save the better for you?I recently carried out a poll of bird keepers in the UK and Holland, with some quit interesting results.
Onto my mix, for those of you who are interested in having a go I have detailed below each quantity in parts per type, these measures can be anything form 1kg to a scoop of a contain, it doesn't’t really matter as long as you don’t use to much of certain types of seed putting to much of some type of seed will only result in your birds not eating it.
Panicum Millet 3 parts
White Millet 3 parts
Plain Canary 2 parts
Red Millet 1 part
Japanese Millet 1 part
Niger ½ part
The above ingredients mixed together will give you a standard Belgium type mix, you can also add the other ingredients to make tonic seed to help bring your birds into breeding condition or to encourage sick and newly fledged young to feed.
Add some aniseed either in pure, liquid or seed form, just remember only use this in moderation as a little goes a long way and the smell can be fairly overpowering. Birds love the smell of aniseed, it attracts sick birds to the seed and encourages them to feed.
I also add pin headed oats to my mix as well as perillia and some rape seeds, again this is all down to personal preference and knowing what your birds like.
My advice would be start with the basics and move onto the finer points later, but by giving your birds more variety they will be a lot happier which means they will be more likely to produce go healthy stock.