So first off...WELCOME to the Forum...
I never heard of "Spelt" honestly so did a quick fact finding tour of some sites for a education.
I found a site which does comparisons of food for humans. https://skipthepie.org/cereal-grains.../spelt-cooked/
What I found amazing in just this comparison was how much more nutrient values were not
there that I expected to be.
I feel like it is a "empty calorie" thing for people and that is why the popularity is making the comeback so many sites I went to made mention of...weight loss being a big reason.
I'm not sure why you would be adding it or feel it is advantageous added to a horse food....
I also kept finding references to facts from other nations but not here in the USA or by our food producing rules and regulations...
In a horse food...seriously I question the "organic" and need for it since the rain that nourishes the land is filled with the pollutants of the planet...
Horses graze pastures that pull nutrients from the water source that no farm has control over...it just is there or not.
For horses, unless you plan on not vaccinating, nor using fly spray, medications for injuries and antibiotics for illness, tested results known worming medication...then I see no point in spending the extra for "organic" of anything.
Being organic is not necessarily the better way to do for a animal.
So your feed mix with the number one ingredient being corn is
great for livestock and ruminant animals, but not so good for horses.
There are many here who can far better explain the pro and con of feeding a feed rich in corn & oats versus other ingredients to horses....horses is the key word.
I also am not a lover of feeding actual molasses in any amount to my horses.
To moisten feed that may be dust particle probable there are far more choices in fats I would use...
The horse does better with a high fat and fiber diet with low sugar and starch is a proved concept today.
Now onto your
I have a feed-mill near me too.
He will mix and does mix all kinds of feed products, mostly for cattle.
What I can tell you is unless the entire line is taken down and apart and cleaned thoroughly between mixes, your organic feed has traces of added nutrients because there is always residue on the feed line left someplace.
What I personally would be making positively sure of is there is no additive on the premise
used in any feed that could cause harm and death to your horse...namely Rumensin or Monesin
and any of the variety of this additive. In the tiniest amounts consumed by equines, death is a real issue and possibility.
As the feed mill does livestock feeds, Rumensin/Monesin is commonly part of those feeds made would make me not purchase and never knowingly buy products from this mill.
The feed mill by me does not
allow that product on his premise ever and that takes out that worry to me.
However, since he mixes only sweet feeds I no longer use the mill just because I don't feed that composition anymore.
My horses do better on true horse pelleted feed with the added in vitamin and minerals they need to thrive and do their best on.
That puts me in commercial mixed feed, my local grown hay fed along with pasture grazed. I just don't do sweet feed anymore.
I gave you several articles about Monesin poisoning so you can be informed and very aware as you buy from a feed mill, which processes livestock feed.
Any feed, commercially made needs safeguards in place to protect our horses.
There are hundreds of articles and references to see and read.
Sadly, in my state alone their have been several devastating occurrences of contaminated feed fed and many horses lost to horrible deaths...please, please be aware and so very conscious in what you feed and from where it comes.
I happen to only purchase feed that has dedicated horse feed mills...no other animal feed is made on premise so there is no chance of contamination happening...my peace of mind!
The links to just a few articles of hundreds... https://www.swvets.co.nz/content/mon...-poison-horses Monensin Poisoning | HorseDVM Diseases A-Z Horse Owner Today | Monensin: Fatal Feed
Keep on asking those questions and we, the members will try to answer them and give our opinions for you to think about and consider when making your decisions.