[QUOTE=dexhol;8523307]
We had a couple OTTB’s that would go nutso on alfalfa too, even a small amount. One gelding went from being fairly quiet to virtually unrideable and quite aggressive on the ground. Off the alfalfa, back to his old self.[/QUOTE]
It’s a food sensitivity. It can make a horse become hot or nasty because they are having a reaction to the type of hay. You might be miserable too if you are having a systemic reaction to something you ate (joint aches, digestive upset, skin sensitivity, etc.). But it does not CAUSE hotness in horses, and has nothing to do with the protein content of the hay.
Just because the horse is hot and eating alfalfa, doesn’t mean the horse is hot because of the alfalfa. 20% NSC grain is much more likely to make the horse hot as it is all readily available energy. Please switch the grain. If you don’t see a reasonable amount of change after a few weeks, THEN try the hay.