How long can a horse pack its food?

Reading the "Pellets vs Hay" thread started me wondering about this. Say you're going on a multi-day pack trip with no grazing along the way, so you have to pack all the food for you and your horse. How many days can you go?

For comparison, as a human backpacker, and using freeze-dried & dehydrated foods (finding water along the way), I could pack for a week easily, maybe two at a stretch. If I had to carry my water, maybe three days max.

A pack horse can pack 100-150lbs. A horse will eat 15-20lbs a day.
If youa re packing feed on one horse and riding a second, That means you will feed 40 lbs a day. So a 100 lb pack will last 2.5 days.

In reality, you pack grain and let the horses fill up on what ever coarse feed they can find. The grain gives them calories, The slim pickens grass helps fill their gut. So you can get by with 50lbs of grain for 4-5 days. I've come off 5 day camp outs with my horse looking pretty gaunt around the flanks, but they've had plenty of energy for the trip.

You and I have to pack in our food. The horses will always be abe to find some thing to eat. Maybe not enough, but they will find some. Even today, my mares were picking through the snow while I was riding to get a mouthful of old dry grass.

Let's see: Me, 200 lbs, plus clothes, boots, etc. Saddle 20 lbs. Also stuff in backpack or saddlebag. Poor Ellie

Maybe most places, but around here? Black Rock Desert - Wikipedia, the free encyclopedia Of course I'm thinking worst case, but a lot of the places I might go don't have a lot of vegetation. Even in the higher country, there are long stretches that're mostly pine trees & manzanita scrub growing in decomposed granite.

Horses can carry more LIVE than they can carry dead weight. You as a rider help to balance the load. A pack with dead weight doesn't help the horse balance as it leans. The same horse can carry 200lb rider, but only pack 100-150lbs of dead weight.

And I've riden in some pretty barren places. And the horses do loose weight, but they always find a little to eat. I normally don't grain my horses, but when I know the feed will be slim, I bring some grain along for energy.