How many alfalfa cubes do you normally feed? I'm not trying to replace hay, just wanting to add in some extra calories. I grab two handfuls and soak them and then mix in with grain. Is this even remotely enough? I only do this at night, I cannot do it in the morning.

Kinda hard to judge by the hand fulls, I got me a little  hanging scale to weigh them out to see how much I was feeding at first, I went with what the amount was to feed on the bag at first and since its was more for a treat I just went with the hand full and a little more, so now I just fill a feed scoop and just use half of one for each horse, but since you are feeding to add calories see what it says on the bag the cubes come in.