Since I've started feeding my snakes rat fuzzies/pups this year instead of mice, I've noticed a much better growth rate in them. Rat pups seem to give them better nutrition (rat pups have larger bones and internal organs than mice, which IMHO equals more nutrition). I've also noticed that while my baby snakes seem hungry on feeding day (laying in their hides with their heads sticking out) now that I've been feeding rat pups, they aren't starving like they seemed to be on mice (completely out of their hides and waiting with their heads at the front and top of the tubs where the food comes in at). I've also started breeding my own feeder rats.

Here's my feeding chart; I feed once every 7 days, regardless of snake age:
Hatchling-99 grams: Rat Fuzzy
100-249 grams: Rat Pup
250-349 grams: Rat Hopper (between pup and weaned)
350-499 grams: Weaned Rat
500-849 grams: Small Rat
850-1199 grams: Small Plus Rat (based on RodentPro.com, their "small" range is so wide that I've divided it into two groups, with the "Small Plus" on my feeders being the larger of RodentPro's range)
1200-2799 grams: Medium Rat
2800+ grams: Large Rat (and yes, I have 2 ball pythons that are on large rats)