Hello Pigeon Man,
I am just starting to feed raw to my GSD and what I've learned from my research of books and threads such as this on the internet is that the dog should be fed 2% to 3% of their body weight per day in two meals. I've settled on 2.5% down the middle to start and will adjust as needed for maintenance.
Therefore at 2.5% here's your formula:
73 lbs * .025 = 1.825 lbs per day, roughly 29 oz per day, 14.6 oz per meal.
Feel free to adjust the formula if you'd rather feed a higher or lower percentage of Saleen's body weight based on her activity level.
This seems to work out just about right for you as I'm feeding 18oz per meal, 36oz per day for my 85 lb GSD.