I'm just really starting to hatch the birds from my eggs, and I am ensuring all of my breeding birds get FF. It's only my layers on dry, and I hate feeding them dry - because they complain.. They know the difference, but it freezes so darn fast I can't do it unless we have warm(ish) weather. All my pens have heated dishes for the FF.
I only got one hatch out before the fire last year when they were on FF, and I had 100% hatch. Not one single loss. 75% were girls too.
That's what the other lady said! Most of hers were girls from over 100 eggs hatched I think she only had a small percentage of males! I've had similar results in meat rabbits, chickens and in sheep that were given ACV in their water on a continual basis but many breeders will laugh outright when you report those averages and say if that were true all the hatcheries would be using that method. All I can think when they say these things is maybe the hatcheries are run by people just like....you? People who are so small minded they won't even experiment to see if it bears out.
All but one of the chicks I've hatched under broodies in the past several years have been females.