I'm not 100% sure of top three brands because each horse is different, so I could possibly have top three brands per horse, but that would still be a lot of feeds. So I'll try to list the ones I've seen good results with:
1. Triple Crown
2. Nutrena/ Purina (these two tied for me honestly)
3. ..um...not sure really.
ADM used to be pretty high on my list, but with the Monensin issue, not so much anymore. If they would have owned up to it and done better then I would still list them. They'll have to essentially 'prove' themselves trustworthy again for me to use them.
I will say I do not like no-name cheap sweet feed/ all-stock feeds for horses. Such as Dumor, Producer's Pride etc. I'll feed plain oats before I give one of those feeds.
Guess these would be my highest chosen feed manufacturers.
Not everything in every line of feed do I like and I feed "brand" according to what my horses need and thrive on.
I don't do "no-name" companies nor food-store.
Also don't like some of the "name" companies just well, because I'm not impressed with that particular product.
As for lowest brand, I believe listing them and "slandering" their name is just not fair to them.
Obviously, if they are in business someone purchases their product and is happy with it.
Since much of our feeding regime is a personal preference anyway to product used....your horse, your business what you put into that animal to keep it healthy. jmo...
My thought was best feed for what horse, use, age, health? What is best for your horse might not be best for mine.
There is a multitude of feeds available now.
Purina and Nutrena are owned by Cargill. So is Triple Crown.
Cargill also owns the Southern States feed sold by Agway.
I have no problems with the feed.
I use a smaller regional mill, Poulin. Mostly northeastern states. Mill is in VT.
The service you get from them is when you have a question is excellent plus they are actually talking to you and not reading cue cards like some automaton. Plus I'd rather give my money to a local business rather than a multi-national corporation.