Budgiebird

Hi Our Budgie laid 6 eggs and three hatched 8, 7 and 6 days ago. Two eggs failed to develop and this last one hatched 36 hours ago. Mom refuses to care for it and the other babies are being aggressive. I found it huddled in a corner and Mom kept pushing it out of the nest area. I took it out yesterday and set it up on its own with a light to keep him warm at around 94 F. We raise chickens, ducks and turkeys and I have had to tube some very weak hatchlings but this is way out of my realm of experience. I fed him some warm watery yogurt last night and bought the Kaytee Exact this morning. I followed the directions on the can. I know his chances aren't good but the little guy is eating and pooping. I'm not sure how much to feed him or how often. His crop does empty and he's very active. Any advice would be appreciated. Thank you Susan