Well, I've gone ahead & done it, gave the laying flocks Wazine in their drinking water on Sunday. I've not done this before, worm them just because or while they're molting. But they had a severe infestation of roundworms early in the summer and our climate makes for a big petri dish in the yard.
I haven't seen any more evidence of roundworms, nor was there any shed where I could see them after they drank the Wazine water. But I wanted to prevent any future outbreaks.
I figured now was a good time to worm since they aren't laying many eggs anyway, so there would be less to discard during the withdrawal period. My hens have to sell most of their eggs to help pay for their feed, and they don't want to lose customers.
Now here's another question: Do you feed the eggs they lay during the withdrawal period back to your layers? Again, I've heard conflicting arguments. Some say No Way, you're just prolonging the withdrawal period by feeding them eggs tainted with the medication. Others say Why Not, the amount of medicine in those eggs is really minimal, it won't affect the next eggs to come.
I've been giving them back their eggs, figuring the extra protein & calcium will help them as they recover from their molt. I put them in the blender shells & all and cook them scrambled. Today I put a few cloves of garlic in the blender with the eggs for extra goodness. I'm feeding 6 eggs to 60 hens so I think any residual medication they get back will be minimal.
But I'm open to hear other points of view...