Well of course the Angus jocky is going to tell you his ducks are better than everyone elses.
I am a Limo breeder, I would tell you to use a Limousin Bull on what you have if you want to see muscle growth efficiency, and have clving ease.
In all situations there is something that works great for everyone,
What I would ask is what part of the country are you is, what is your climate like
You can use feed through products such as IGR in a loose mineral, product like these make resultant progeny of the parasites non-viable, thus reducing the population over time.
There are draw backs if your neighbor doesn't use them too, it is like treating the grasshoppers on your place and then the neighbors come over and eat your grass after the rain comes and the next generation hatches
I like Cylence, it is a pour on Fly control which lasts for several weeks, then you due it again, what you would lose from not treating in loss of gains will easily be covered be the $.70 per head cost of treating, this is what we use and it works VERY Well, no injections, just a pour on or squirt on with the gun and your done, and so are those bugs