yeah, I'm a little mystified by the "never" feed yougurt. Been feeding yougurt for 8 years, never had a problem.
I avoid the sweetened because they don't need it, regardless of what sort of sweetner, and I don't eat that myself - I prefer to drizzle maple syrup over the banana on the yogurt....yum. oh yeah, i forgot, we're talking about chickens, not me!
um, you want to look at the label of the yogurt to see if it has any probiotics in it - the highly processed kind doesnt, and that tends to be the kind that has the fake sweetner or lots of sweetner. There is a lot of yogurt in the grocery store that isn't worth eating for the chicks or for you!