I decided to let her keep 5 eggs yesterday! It’s only 6 days after their last treatment. TBD if any hatch, or if she will sit long enough to find out because she has already been broody for about 5 days. I marked them all so I know which ones they are, I’ll keep you posted!Ivermectin can effect fertility in the hen for about 2 weeks after the last dose, making her less fertile. However it's not proven to cause any birth defects in chicks. All you may or may NOT see is a low hatch rate, but keep us posted!