It may be fresh, but it's still junk for horses because:
Too much starch. In order for a healthy hindgut to be maintained, horses need diets stemmed mostly from forages (Low starch, high fiber). Oats alone have about 44% starch. In a bag of sweet feed, imagine 3 or 4 pounds of pure SUGAR. Sweet feed, really, is like people eating a snickers bar. Does it have nutrition in it? Sure. But it's also got a lot of negative nutrition.
Insulin resistance is becoming more and more common in horses (people too) because of diets consisting of too much starch.
When a high starch meal is given, insulin spikes. 6-8 hours later, when the insulin comes down to a desired level again, we feed them again, and again it spikes. Years later, horses end up with Cushings like symptoms=Insulin Resistance. Not a lot different than diabetic people who ate junk food primarily
I agree with people who say to give it sparingly as a treat for chickens (although I've never thought about it myself
)
As for use in horses, I hate it.
I run a feed store, and I generally don't carry the stuff because if it doesn't get sold, I have to feed it to my horses or waste it...
A few years ago when I started selling, I stocked up on what my vendors told me were good sellers. When my main customer of sweet feed moved from the area, I either needed to feed it to my own horses or risk it going bad (No real store front at the time for ideal storage). It was winter time, so I figured "why not?"
Two farrier visits later, my horses were total nut bags. It was an embarrassing confession when I told the farrier why...and as soon as I cut out the sweet feed, the next farrier visit they stood statue still again.
Not only is it healthier for their dispositions, it's healthier on their guts. The higher the starch, the higher the acidity it causes on their hindgut. The higher the acidity, the more risk of ulcers, founder, colic, etc.
Ok, stepping off soap box :-D