Hi there, She's not improving because she needs to also be getting crucial B complex along with the E and Selinium.
Any brand from the grocery store will be fine, give her a third of a tablet.
I wouldn't worry about Selinium overdose at this point
If that's why you bought it, you sadly overpaid, those coops are not predator proof, the nest box doors can be popped open by raccoons. make sure you replace the hardware with locks and give it another coat of paint to slow down the warping.
Those are round worms.
Ivermectin lost its effectiveness on poultry parasites years ago, especially with routine exposure.
You need to get some Valbazen, typically under the brand SafeGuard.
Safeguard 10% Liquid Goat Dewormer or 10% Equine Paste dose is 0.23ml per pound of weight given...
Cockerel, the red wings (which aren't supposed to be there for that color) and black feathers say male. Female dark brahma are gray Partridge. and don't have the black feathers.