Aggressive behavior and soft shelled eggs, where am i going wrong?

Hi BYC forum, Im a new member from Brisbane, Australia. i have three 'red' chickens we got from a produce store locally, I think they're Isa Browns. they are ten months old approx, or should I say we have had them ten months, Im not sure how old they were when we got them, 'just about to lay' according to the store, they eventually started laying ten weeks or so after we got them, but it was a hot summer so that may have delayed them.

We originally had five, but one got sick, she started coughing, it took us a week or so to work out she was sick, then we tried sulpha in their water, but within two weeks she had sweats and a bubbly eye, and looked to be distressed, so she was dispatched humanely. She was our most friendly and interactive chook, so very sad. The others appeared fine for a few months, when another started looking straggly and unwell, thinner, then developed a cough. She joined the first under the mango tree. That was five months ago, the other three appear fine.

We had initially intermittent eggs and various numbers, but since we lost the second chicken we have had three perfect, very large, eggs nearly every day. In the last four days something has changed. We get two perfect eggs, and one abnormal one. Day one we had a shellless or soft shell egg dropped under the roost, the second day one very brittle shelled egg which crumbled in my hand, day three brought a nearly normal egg with a very brittle pointy end, day four reveals a puddle of brownish egg liquid in the laying box, likely another shellless egg someone stood on.

The other two seem to be laying normally, no-one is unwell. I am feeding them a 17 percent protein mix from the produce store, and they free range in the back yard for two or three hours in the afternoon. They get a tomato or two per week, and some kale or rocket leaves a few days a week, we have very few kitchen scraps. Since the egg problem I have started feeding them ground microwaved eggshell in their mash, and bought them some frozen peas which they love.

Their food manufacturer seems to have changed the food, its now quite finely ground, and we started using the new feed about five weeks ago. Because it is fineground we bought a chicken feeder they need to stand on the bar for, which opens the lid. I have been mixing the finer feed with water to make a porridge or mush, as well. They are fairly bright, and seem to love the feed, but Im not sure they remember how to open the feeder later in the day. Initially it was empty every evening, now its often half full. I have been tipping the old feed out beside the feeder, and have noticed the old feed smells quite sour. Wonder if I may have caused a fungal infection? We have hot days and high humidity at this time of year. Im cleaning out the pen and going back to the open feeder today, the neighborhood pidgeons will love me.

We have a large native bush turkey who has also moved in, she spends all day here, we have altered the coop door so she cant fit in there at night, also about five weeks ago. She has been here for months, seems well, and has attracted a male who also comes and goes, there may be some parasite our chicken has picked up from the wild birds.

Lastly, one of our three girls has become more aggressive, she bites my hands, hard, when I put down their food too slow, she pushes the others out of the way for food, and she wont drop for a back 'scruff' like the other two do, and yesterday she jumped at my face when i bent down to pat the cat, I think she was interested in my earring, and then pecked the cats tail to make him run, all new behavior. I wonder if her dominance behavior may be associated with hormone imbalance, maybe thats what is causing the unformed eggs??

Sorry to be so long winded, I am hoping someone can tell me if the behavior and the egg issue may be related, and involve the same chicken, orwhether this is likely to be parasite or fungal related, or a feed issue. Thanks in advance.

 

Thanks for the advice, I am on my way out to buy a different feed, will check the calcium content, and will try to find some oyster shell as well, planning a full cleanout of the pen and coop today. I havent seen any sign of illness but will give them a checkup today. I have actually never wormed them, so will head off to the produce store for medicine during the week, its Sunday and nothing much is open here.