Duck lays thin-shelled eggs, but gets lots of calcium. What's up?

[GardenerGal]

I have a small flock of khaki Campbells, and they all get layer pellets and extra calcium (pulverized oyster shell) when they're laying.

One of the ducks lays eggs with very thin and brittle shells. She's 3 years old and seems otherwise quite healthy. Until this year she laid normal shelled eggs. All the other ducks lay normal eggs.

Anyone have an idea of why she'd be having shell troubles?

 

[Wifezilla]

Maybe she is having some mineral absorption issues. Have you tried spiking their drinking water with apple cider vinegar? Sometimes that helps.

 

[GardenerGal]

Couldn't hurt to give it a shot! Thanks, Wifezilla.
I'm guessing the problem is a metabolic one. If it does involve mineral absorption, I wonder whether giving her vitamin supplements with her oyster shell and layer pellets would help. What vitamins aid in mineral absorption?

 

[goosedragon]

Quote:
vit D for Calcium in human women.

 

[Wifezilla]

I take D in the winter. Carlson's brand comes in liquid drops.

As for the apple cider vinegar, make sure it is the raw stuff like Braggs.

 

[GardenerGal]

Thanks. GD and WZ. I'll try a low dosage of Vit. D with her calcium and try giving it to her in bread balls, or give her Vit. D-enriched yoghurt mixed with the pulverized oyster shells for a a while and see if it helps. She seems otherwise healthy and sturdy. No signs of thin bones in her legs.