We are seeking a spray for lice and fly control for our cattle and calves. Any ideas or products you can recommend?

The livestock experts hang out in a different forum. You might post this question in Farming & Ranching forum.

Before you post again, they are going to want to know where you live, what breed of animals are involved, what have you tried, and are you otherwise organic? And I would want to know if you have chickens, because that would be my first answer. Free ranging chickens are worth their weight in gold even if the predators take them out.