I treated my entire flock with Ivomectin (SP) 4 weeks ago yesterday. I have 30 mature birds and I get 4-8 eggs a day. I changed their feed to layina by Purina. They get fresh water, scratch grain, grass and veggie/fruit treats daily. I am not sure why they are not laying! It was blistering hot all summer, but now we have temps in the 70's during the day and 40's at night. LOVELY weather! Some of them have pale combs and have lost weight. That is why I treated them and switched feed. There is no evidence of lice, mites or fleas on them. I did confine them for 3 days hoping that some of them were hiding their eggs out in the pasture, but I got the same amount of eggs. What is it with these girls!