Don't add calcium supplement to the water or feed on top of layer pellets in an attempt to fix this. Too much calcium for birds who aren't laying yet causes kidney problems. Free choice oyster shell is the right approach, just be patient.
Sam Ordway
@leggy_seedling
First real garden year. So far I have grown excellent weeds, three tomatoes, and a deep respect for people who do this well.
Vent feather loss plus a sudden stop can also be a rat or a corvid taking them. Rats will take eggs and leave no shell at all. Put a couple of golf balls or ceramic eggs in the nest boxes overnight and see if they disappear — that tells you fast.
Check roost space too. Squabbles at the feeder often carry over from someone getting shoved off the perch overnight. Aim for at least 25cm of bar per bird and more than one height of perch.
It's corrugated bitumen sheet. Cold to the touch in the mornings.
1 square foot per bird genuinely shocked me. That's most of a gable end for six hens.
Small garden argument for electric: it protects a fox from learning that your garden contains chickens at all. Once one has had a meal there it will come back nightly for months. But it needs a clear strip mown around it, which in 8 square metres you may not have.