Too much calcium?

[Gwhite3678]

From what I’ve read chickens will not overeat free choice oyster shells but I’ve noticed some abnormalities on some of my eggs and the common denominator seems to be excessive calcium in the diet. I’ve seen large calcium deposits and tiny specks of calcium all over the shells and what looks to be a white film on various eggs from different members of the flock.
I feed a starter/ grower formula since I have a rooster and offer oyster shell and grit free choice. I also crush up used egg shells and offer those as well.
I have added the feeds ingredients and analysis here.
Please let me know if I should change what I am doing, I want my girls to be happy and healthy.
Thank you!

 

[U_Stormcrow]

The studies say that, on average, chickens regulate their diet to control calorie intake* (exception for Cx and related stock) and to control calcium intake. Its unlikely that free choice oyster shell is the culprit - but chickens that don't need extra calcium may still eat eggshells (which is much more quickly metabolized, due to its much greater surface/volume ratios) not because of the calcium, but because of what's left on them. Particularly if you don't wash spent eggshells before providing them to the flock.

Individuals, of course will vary. But as a general matter, your whole flock should not have evidence of excess calcium from offering oyster shell free choice.

REAL proof of excess calcium will require that you butcher the chicken, with careful attention to the inner cavity for signs of internal calcium deposits within - but to reach levels of gross significance that are visible to the untrained and unaided eye, they will likely need to consume excess calcium levels for half a year or more. Before that, you may see signs of excess calcium as urates on the droppings, but that can be hard to judge, since the change will come slowly, and because so many factors influence chicken poops.

 

[Kanekoded]

Chickens have the ability to adjust their own calcium intake when given a choice... and it sounds to me like you're giving your chickens that choice. Calcium coated eggs are usually nothing to worry about. I have a hen that has had a "dusty bloom" (what I call it) from the time she started laying and she's as healthy as a horse.