Feeding Dehydrated Alfalfa?

Does anyone have any experience feeding dehydrated alfalfa? This is new to me.

I've been trying to add just a slight bit of weight to my Dutch Warmblood. I tried increasing his grain and his coastal hay rations, but he won't eat all of the coastal. So, I reworked his feeding plan to take into account feeding some alfalfa to see if he would finish all that. I used the feeding plan guide in the Pony Club A manual to account for the calories, protein, calcium, and phosphorous that he would need. The feed store was out of standard bales of alfalfa, but they did have this dehydrated alfalfa. I had never heard of this before, but I figured it was worth a try.

Now, the dehydrated alfalfa is supposed to be more compact and nutrient dense than standard alfalfa hay, but the bag has no feeding directions, and it does not tell me how many pounds of the dehydrated would be equivalent to the number of pounds of hay needed according to the feeding plan.

Does anyone know if there is a standard conversion factor or equivalency factor I can use to calculate how much dehydrated alfalfa to use? For now, I am introducing it slowly, but I need to know where stop increasing the ration.