Mine did on Alfa oil, I was feeding about 5 heaped stubbs scoops a day though! Even though it has no starch it's still high energy, mine just didn't need it lol.
I havent personally, both have done my guys good with conditioning and easy energy levels. Maybe your horse is sensitive to alfalfa, scale down the amount given an dsee if this helps, if it doesnt then perhaps look to something else to add conditoon like linseed oil with another type of chaff.
Most chaffs do contain alfalfa but maybe in smaller levels than the pure stuff you are feeding.
Im trying spillers senior fibre for my oldie this winter but if he needs it ill switch to the conditioning fibre as have heard good things about that.
I started using Dengie Healthy Tummy that is alfalfa based as our TB needed some conditioning after a period of box rest and it is good for ulcers etc. He didnt change one iota. Our lazy, comatose cob turned into the "Anti-Christ" within a couple of days and wound himself up like an eight day clock. I never seen a cob buck so hard or leap off the ground so high! Needless to say we took him off it asap and a week later he is still on another planet but getting better.
I guess some horses have an intolerance to it.
I feed alpha beet and Charlie is fine, no sign of being fizzy and he is keeping weight on great. However, he is not good on sugar beet. He really enjoys his alpha beet
Whereas mine can cope with Alfalfa pellets but I have to be careful with Sugarbeet. Easibeet sent him psycho but I'm OK with limited quantities of Speedibeet or Kwikbeet.
When I looked on the Dengie website it listed the ingredients as Alfalfa and Sugarbeet, didn't say whether it was molassed or unmolassed, and no sugar level listed either.
Comes down to two possibilities really, 1) the protein levels are too high (14% is high) in which case alfalfa is the culprit 2) sugar levels which we don't know in which case it's the sugarbeet.
My 2 TB geldings lost it completely on Alfa A oil (previously on original but needed a bit more over the winter). They were the most laid back horses beforehand - came off it within 10 days as there were no other changes to feed/routine so it was obvious what had set them off. Within a couple of days they were back to normal. They are both retired now and the 20yo has gone back on it as needs a bit more condition - all issues previous time were while being ridden so assume he will be ok this time.
My tb went off his rocker when I fed him Alfa A just the original as well although he is super sensitive! He is on topspec top chop lite now and that seems to suit him. He's a very fussy eater and struggle to find things he will eat! Wouldn't touch the healthy tummy chaff.
apparantly the horse digests alfalfa starch differently and it can really affect some horses temperments. Sent mine mental - like physically shaking she was like a child on E numbers! took her off it and 2 days back to normal!!
I was recommender alfabeet by a trimmer when I went barefoot with my boy - apparently it is unmolassed sugar beet. He did fab on it, he looked great and put on plenty of muscle despite the YM's concern that it wouldn't provide enough energy and condition. However when he previously had sugar beet he was a loon!!
I've heard of a few horses that have a strong reaction to alfalfa so it's probably that.
My 13 yo TB is on a twice daily feed of Alpha A Oil and Alfa Beet and currently only worked properly at the weekends and he's still his usual cool tempered self, albeit slightly more excitable when he was out this weekend but I put that down to being in most the week because of the weather, only difference I noticed in him when changiing him onto these feeds a couple of months ago is his now nice shiny coat and it's put a decent amount of weight on him for the winter which I struggled to keep on him last year.
Am surprised it can affect some horse's temprements though and will definitely monitor closely any other horse I put on it if it can cause different reactions like the ones described here!