When can I feed treats to bottle babies?

[chicks & ducks]

Hi all.
We have 2 2 week old bottle babies(insert 'awwww' sounds here)

We're giving them milk 3x a day and that's it at the moment. My question is-when can we start treats like raisins? Do we have to wait til they're off the milk? They kind of have loose 'movements' at the moment but I'm putting that down to a change in formula and the stress of the move.

Any body?

 

[20kidsonhill]

I would start offering them some good quality grass hay. the long stems help to develop their rumen. Until they are on hay, I don't think I would be offering them too many different foods.