Poor hatches happen for all kinds of reasons. There's no way anybody reading this thread can know just what factors affected the hatch rate, other than the dye. She could have had temp spikes, or temps too low, humidity problems, or other things we are unaware of. The dye is just the one thing you are aware of.
If done correctly, injecting dye is not at all like holding their heads under water. For one thing, the whole chick at that stage is still completely surrounded by fluid. For another thing, the dye is injected into the fluid at the small end of the eggs which isn't even where the the chicks head will be later when it begins to breathe air.
I've never heard of dying chicks by adding food color to the hens feed before collecting the eggs. If that works, I wonder why commercial hatcheries (that sell colored chicks) do it by injection, instead. I'll have to look that up, it's an interesting idea. Just ordinary food coloring?
If done correctly, injecting dye is not at all like holding their heads under water. For one thing, the whole chick at that stage is still completely surrounded by fluid. For another thing, the dye is injected into the fluid at the small end of the eggs which isn't even where the the chicks head will be later when it begins to breathe air.
I've never heard of dying chicks by adding food color to the hens feed before collecting the eggs. If that works, I wonder why commercial hatcheries (that sell colored chicks) do it by injection, instead. I'll have to look that up, it's an interesting idea. Just ordinary food coloring?