Greenish/Brown Diarrhea in my chickens

[BABevill]

I am very new to chicken farming. I had a friend give me 9 chickens because he decided to move and couldn't take his chickens with him. I have no idea how old these chickens are. There was originally 6 New Hampshire Reds, and 3 Black & White speckled(No idea what kind). One the the reds had a superiority complex and would peck the other chickens and crush their eggs so I had to put her down. Shortly there after, another one of the Reds got sick and died mysteriously, no sickness shown before hand. Of the 7 left, I normally get on average 2 eggs per day. And 3 of the birds seem to have a greenish diarrhea. They all seem to be eating and drinking ok. I feed them FRM's Laying Mash along with kitchen scraps, (ie cabbage, lettuce, celery, potato peelings, and stale bread). I also add a small portion of oyster shells to the feeders, and was giving them crushed corn. However they stopped eating the corn once I started giving them the kitchen scraps. As I said before, I'm new to chicken farming, but it seems that 7 chickens should be giving more than 2 eggs per day, and the green slimy poop is abnormal. Otherwise they seem to be doing fine. Any suggestion would be greatly appreciated.

 

[Wyorp Rock]

Welcome to BYC!

Do you have photos of the chickens, maybe we can help you identify the breed.
Some hens will quit laying due to stress of being in a new environment, etc.
Do they free range - is it possible they are laying their eggs under the bushes (hiding their eggs)?
The poo may be from the vegetables, can you post a pic of that as well?
Were all the hens laying eggs before you got them?

Here's a poop chart that may help:
http://chat.allotment-garden.org/index.php?topic=17568.0