When you are treating for cocci you should nt be feeding yoghurt or antibiotics. I'm not sure why you would be force feeding your birds. Coccidias is in the soil, so your birds will be reinfected , that is why you treat at full strength for 7 days , then 1/2 strength for a further 7 days and then another 7 days at 1/4 strength . By doing this you are building the birds immunity. Amprolium is a vitamin B inhibitor and starves the coccidia . It is also all too easy to aspirate a chicken, if you are force feeding. I see that you have been getting advice from Kathy. If you feel the need to tube feed , she is the person to talk to. I hope you sort this out.