I have been using one large scoop of garlic in my horses daily ration for years. I was told that if I used that much, I would not need fIy repellent. I have not found that to be the case. True, I use less fly repellent than I used to but I still need to use some. The major benefit of giving my horses garlic is, flies do not breed in my horses poop!! We have virtually no flies in the barn and not many in pasture. The leftover garlic in the poop does not attract flies for breeding but does seem to act as a magnet for my dogs to dine on.