Question about switching feed

[gritsar]

And aren't I just full of questions lately

I started my chicks out on a locally milled chick starter and they seem to be doing fine, but after doing some reading I've decided to switch them to Purina SunFresh Recipe Start and Grow when what I have runs out.
Do I need to mix a little of what they are eating now in with the new feed, such as I do with my other critters when I have to switch feed?

 

[Cats Critters]

I think your right, slowly switch to the new feed.