Look up ascites. There are articles on this site about this. There are many illnesses that cause water-belly, some can be treated with antibiotics and some just lead to long term suffering. I wish I could be more help but I do not have enough experience to give solid advice about this yet.
I also am no expert and am just sharing with you what I've learned in the last couple of years. Try the egg cartons first so you don't have complications from temp/humidity drops. I'm really surprised no one else has chimed in on this thread, lol. I've never hatched ducks so I wouldn't be...
If you don't incubate with an egg turner you could incubate with the eggs in a carton, it helps contain them so they can't be too violent with the other eggs. Or if you see some of your chicks hatch out while there are no pips in the rest of the eggs you could quickly grab them and put them in...
:welcome If you have a spray bottle you could mist the incubator to keep the humidity up while you rescue your silkie. You could put betadine and neosporin without the pain reliever on the chicks navel to prevent infection. Has the 24hr egg been slowly making progress or has it been quiet...
How old are your ladies? Do they free range at all? They might be hiding them. Is it possible that a predator might be harassing them? Even if they can't get in it can spook your girls. Do you have a rooster that might be over-mating them? Are they getting enough calcium? Are they getting...
I agree with BantyChooks. We have been breeding for a meatier dual purpose and raise out new chicks a couple of times a year. Just let the meat rest before you cook it so that it's not still in rigor.
:welcome
I wish you the best of luck on your order. Everything should arrive healthy, but if it doesn't, most hatcheries have refund or replace policies even if chicks are sick and not dead. I've successfully ordered chicks from Meyer's in OH a few times, Ideal in TX, and Hoover's in IA.
:welcome First, welcome to BYC! Isolate your weak chick so the others don't trample it. Keep the sores clean, you can use neosporin so long as it doesn't have the pain killer additive. You can try to give it vitamins like provisol without the iron, or Nutridrench if you have it. Give it time...
Tis the season, lol. I have no idea why they're all going broody now, only 2 went broody in the spring. 2 australorps, 1 orpington, 1 faverolle mix, and 1 faverolle are all broody right now in this heat, here.