Magick, my response to your post would be that I personally would have to compare the ingredients of both products, as well as the amount of protein, vitamins, etc. each contains. It is my understanding that you want a high level of protein for breeders as well as calcium.
Personally, I feed a mixture of rodent diet (seed mix minus the flowers), Kaytee pellets for mice, and lab rodent chow. There is a very distinct progression of their choice of foods from my mix that I have been recently noticing. They choose to eat the seed items, the Kaytee pellets, and then the chow. Quite honestly, the breeders have eaten their babies on occassion before choosing to eat the rodent chow.
Having not specifically compared lab chow to dog food YET, I am investigating other options for feeding the small colony of breeders I maintain.
In reference to saving a few bucks . . . Unless you have an unlimited amount of cash flow (which I don't), I'm all for saving money. I will not save money at the expense of my animal's health, BUT all things considered and being equal (amount, nutritional value, etc.) I will go with the cheaper food be it dog food or lab chow.
I hope this effectively answers your rant, and I appreciate the discussion.
D80