No one will berate you, that I know of...no reason to that I can see!
They look great in the video so I'm assuming that was taken before they started acting "off". I'm going to give you my take on the situation from the little I can figure from what you have told me but some other OT may have more/better insight than I when it comes to warm climates and all.
You purchased birds at 5 wks of age and placed them in a coop that had been previously used by some old hens. This means they were exposed to whatever those old hens had by the droppings left there and the microorganisms present in the soils, which can thrive in warm humid climates for some time after the old inhabitants are long gone. The old hens were surviving into old age, so I'm assuming whatever they had they had formed immunities for and were carriers but not affected.
Your birds may not have had the antibodies already established in their systems that would keep them immune from any ill effects from the exposure. Your birds must have died recently if you have stool samples pending, so they made it to nearly 7 mo. of age before dying? I'd venture to guess that whatever they might have died from it was not what was already in your coop environment but I could be wrong....sometimes it takes time for some diseases/pathogens to colonize another creature's bowels enough to cause illness and death.
Did they show any wasting away, pale combs and wattles, lack of laying, poor appetite before they died or did they just die suddenly with no warning?
Whatever the reason, you have 7 survivors with a few varying symptoms....
First, it sounds as if they have a calcium deficiency, so you may want to place oyster shell and their own eggs shells right back into the feed.
Second, I've heard that intestinal parasites are more prevalent in humid, hot climates like yours, so you may need to do some preventative worming measures....I occasionally will mix garlic powder in the feed for a week or so(no matter what anyone says, it does not make the eggs have a bad taste...both foods are sulfur laden foods).
You can also use something as simple as Shaklee's soap...expensive for the initial purchase but the soap is concentrated and lasts simply forever. The soap in the water will kill worm loads....it only takes a few drops, small ones. I also feed raw pumpkin seeds which also affect worms.
The thing you have to do to avoid constantly having to dose birds with dewormer is to create a bird that either can thrive with parasites present or create an environment that worms cannot cycle in. With your humid conditions that will be difficult and dosing with commercial dewormers will create worms that can survive that dosing. If it were me, I'd be dosing with the things I mentioned when you see pale combs or a drop in lay and I'd also kill any hens that do not respond to these treatments. I know you said you can't afford to lose any, but can you afford to feed those that don't produce? What sense does it make to be getting a few eggs from more than a few hens? It doesn't....keep those that produce on your management and breed them to produce more of the same.
If these were mine, I'd get a rooster if you can have one, and breed for disease and parasite resistance. Good, DP roosters of layer genetics(try RIR or BA~both hardy, layer breeds) can be found free or cheap if you keep your eyes open. When a hen looks sickly and doesn't recover on her own in about three days, cull her. I know it sounds bad to tell someone with only a few hens to kill one but she will most likely not earn her keep anyway and she will most likely die anyway. Whatever she is suffering from could be spread to the others so it's best to just eliminate the problem. The ones that survive are the genetics to carry on. Cull for health and cull for productivity and soon you will have a flock that can withstand nearly anything.
I would also start feeding fermented feeds and placing mother vinegar in their water right now...these birds need to have a strong immune system and a healthy intestinal wall, so start now on trying to develop that. The probiotics in both of these things will help you get there. You can ferment the feeds you are currently feeding and it will only increase the nutrients availability and it will increase the bird's ability to absorb those nutrients. Good nutrition helps to give good health.
Getting a healthy flock takes time, commitment to a single purpose, and some fortitude when it comes to dealing with weeding out inferior birds. It doesn't happen over night and there is no single magic bullet that will make one for you, you simply have to figure out how to make it happen and then just experiment on what works best for you. Some farmers spend many long years getting just the right flock genetics and husbandry style, but when they do, THEN it's magic...but not over night.
I wanted hers because she fed all organically. The chickens really did seems great, until all of this happened.
