Baby dove, parents might not feed it?

I have a ring-neck male dove and a white female dove. I don't know why but for some reason it seems like the parents can't successfully raise their babies. Not too long ago the mother layed two eggs both of which hatched, but as time passed it looked to me as if they were feeding one of their doves more than the other. As a result, the smaller one died, soon after though, the other one after being quite grown (good amount of feather) they just stopped feeding it. Right now, the mother successfully hatched two eggs. Unfortunately, it looks like one has died because they have not been feeding it. I'm afraid that the other one might not make it and the parents will do the same thing like they died to their previous baby dove. I heard that just by touching the doves or watching them, will cause the parents to not feed them. i have not touched any of them. i'm thinking on just feeding it myself so that it will live; i don't know how to begin or what type of food is appropriate for them any tips, advice? I want the current baby dove to live.