Yes you can, I dont know the dosage. I understand that you have alot of chickens. However, keep in mind that mixing wormers in water doesnt guarantee they will all be wormed. If some birds are sick, they will not drink it. Then there's the possibility that some wont drink enough of the mixture to be effective. It's best to worm them orally, individually, in which case I'd recommend valbazen instead of ivomec products.