I use vertical nipples, they are good for a closed system that stays clean. Sometimes they'll get stuck open and make a mess. I understand that a lot of folks prefer the horizontal nipples as they don't have that problem. Out on pasture I keep the babies in a tractor until they're big enough to blend in with the flock. My tractors have a bell waterer which works really well. Once they are in the pasture, I use big bowls and kidy pools because they knock anything I hang over. As for your little guy, check his hind in and make sure the vent is clean and clear. If need be offer some meal worms and food by hand. Not eating is a bad sign.