Didn't I read in one of your other threads that you have confirmed MG? Was that the vet diagnosis or just what you think from the info in the links? If a vet confirmed MG, then you have MG in your flock and you need to work with him/her for a treatment plan (no cure but treatment since you do not want to cull). They can help you with dosage for antibiotics and frequency of use, etc.
I would stop all hatching and absolutely no birds in or out. Do not even give birds away. Hope you can find a plan that works for you to get them better and manage this.
I would stop all hatching and absolutely no birds in or out. Do not even give birds away. Hope you can find a plan that works for you to get them better and manage this.