Who is the author of this and what year was it published?
Calcium is a mineral. As you can see it's from a website, so if there's no author named, then it must be the website. This was written probably by someone that is very skilled on chickens, maybe they have a degree in biology. But I only wonder how fresh air will keep you healthier when there's so much air pollution outside. The only reason air is bad in closed systems is because bacterias concentrate in air and that leads to infections and outbreaks such as the piggy or avian flu. But these bacterias don't affect the quality of the food, unless if it was an infection like ebola that ruins meat and makes it unedible.
Use the link in the source window for answers to your questions.
Hump a dog in the butt.lol.
I would contact the owners of that web site for that information. Visit the source link I posted below for how to contact them.
