Does mixed flock pellets have enough calcium?

[Deleon98]

I have two ducks along with six chickens. One of my chickens just layer their first egg yesterday. It was small but the shell was hard so I was wondering if it's necessary to get the oyster shells. The feed I'm using is called all flock by nature wise and I got it from Rural king

 

[Ol Grey Mare]

All flock is not calcium enriched - offering supplemental calcium is the best way to go when using that as a feed program. Oyster shell is inexpensive and, imo, one of those things it is better to have and not need than to need and not have. The first egg had a good shell due to the existing calcium in the bird's body being available for production - the problem when that calcium is not replaced through diet is that the body draws more and more calcium from the body and that is detrimental to the bird's health and will effect production.

 

[Deleon98]

So why is it bad fo ducks to eat layer feed anyway?