First, isn’t it great to know you’ve headed this horse down right path to good health - what a great job!
Regardless of whether your soil is high or low in selenium, Watch the selenium content in a mineral product you buy. That is one thing that too little is as bad for the horse as too much
If you buy your hay and alfalfa more than 30 days at a time, I would send them both out for a mineral analysis.
The gold standard for forage testing is Equi-analytical in New York. I generally have my results back, via e-mail, in less than a week after they receive the product.
When the results come back, go over them with your vet (who sounds pretty diet savvy BTW:).
It may end up you need a custom mineral mix. I am sure there are seve4al companies who will custom mix.
I know HorseTech does custom mixes, although I’ve never needed one. I will say that I have done business with them since 2014 with no complaints whatsoever.
They get the bulk of my horse supplement money as all I feed are Timothy pellets for the carrier of their vit/min supplement and whatever else each horse needs.
, I’m right I. There with you about the old days, lollol. Once Upon A Time my horses ran on 98 acres with beef cattle and had a big open barn for shelter.
They got fed a cup of home grown oats and CORN to keep them coming up to the barn every day. They ate home grown Timothy hay in the winter - that I had rope burns in my fingers when the trip rope didn’t trip, pulling it up into the hay mow the previous July, lollol
Nobody was sick, nobody foundered. — what the hayyyy has gone amuck in this world———
Anyway, I said all that to simply say, “start by testing your forages and go from there for mineral adds:):)