I had to put a little Skin So Soft on my dog because she was getting torn up by horse flies.. She had huge welts all over her... Amazing how well a little bit went a long ways.. What little I put on lasted for a couple days.. They instantly left her alone.. Just a couple squirts then I rubbed it in..
If I had a cow or two.. .I'd consider it, but not a herd.. I'd bet less than a quarter bottle would work well for a cow..