BP growth rate rats vs mice

Ive heard that feeding your BP rats makes them grow faster than mice. But ive also heard that it doesnt really make a difference. I wanted to get some input on the subject. Ive only fed mice to my biggest BP about 3 times when i first got him then i switched him to rats and my other BPs i offered rats from the start so Ive never been able to compare growth rates. I feed rats because i figure the faster i switch to rats the better. Is there any difference in a BPs growth rate by feeding rats vs mice?

The difference is one rat to multiple mice. Also how well they feed or if they go off feed.
In my collection there is no difference, I feed what they eat till the refuse the next one.