My horses thrive on 3 pounds of quality grains and about 10 lbs of alfalfa per day. They also get to graze, but it is not a great field, being in AZ. As for water, when being ridden, I would guess 8 gallons a day is a good estimate, especially in hotter climates.
The problem is feeding can vary greatly between the horses, their breed and size has a lot to do with it. For example, if I feed my Quarter Horse as much as I feed my Thoroughbred, he would get very fat. If I fed my Thoroughbred like I do my Quarterhorse she will look skeletal very fast.
As for goats mine are doing well on about 5 pounds of feed per day, with no graze, and the feed is alfalfa bales. Since they are not eating all day long they look like they may be starving because they are not bloated up with all the digestive gases they produce, but they do have plenty of good meat on their bones. As for water they do well on about 4 gallons per day, but then again I don't force them to travel all day either. Plus they certainly do not like working for a living. If there is plenty of graze around then goats probably don't even need to have feed brought, if it is a plant they will likely eat it. There is very little a goat will not eat. So if its a well forested land, or lots of grasses and bushes, don't worry about feeding them, just make sure they get to graze for a couple of hours per day.
How far can you go on a horse in one day? Well, if riding hard, with good food and water for you and your horse, you can cover over 100 miles (Endurance riders know what I am talking about). Both horse and rider better be in great condition too. Normally you can probably cover 40 miles over decently flat terrain without hurting you or your horse.
The biggest issue with horses is their hooves. They split/crack, and can do so badly enough to lame the horse, even to the point of having to put it down. This is a large part of why horse shoes were created. So every rider should have basic knowledge of horse hoof care. Basic shoeing, trimming of the hooves, cleaning stuff out of the shoes regularly, etc... this is all very critical to keep your horse from coming up lame, especially when being ridden hard, on a regular basis, and most especially when the terrain is hard, like rocks, etc... Nice soft grassy plains and similar would be much less likely to damage hooves.
Plus people seem to think riding a horse is easy. It isn't, even after you become a seasoned rider. You ride a horse for an 8 to 10 hour day you will be sore, if your new to it, you may become bed ridden from it just to recover from it and let raw spots heal. The key reason for having a good posture while on horse back is not only an issue of balance, it will also help you be in less pain as the day wears on. You have bad posture you will be in a bad way by the end of a long day.
So there are a lot of things to know and be aware of. Usually we just put all of this in the back ground, and we just assume everyone knows what is needed, what supplies need to be carried, etc... but to be fully prepared, especially on multi day journeys, you best have good farrier tools, know how to use them in most cases, be able to build a good hot coal fire when it comes time to shape a shoe for a horse, and have the hammer, tongs, and probably most important fo all, a horse shoe bar. This is a 18 bar that covers a wide range of horse shoe sizes, so one end will be narrower than the other. So when you shape the shoe you find your horses hoof size on this bar, and that is where you shape it after heating it up. The bar is expensive, but if your mission is time critical, you want to have one along with you, and have someone who knows a decent amount of farrier work.
Again, this is if you really want to illustrate how challenging just riding 200 miles to the next town can be without Orcs attacking you. Most of us just ignore such trials and tribulations because they are so boring, but they are real potential obstacles. Things I have begun to pay attention to since starting up my Aces and Eights game several months ago.
I mean think about it, if your horse comes up lame while trying to outrun a group of 20 Orcs, your in big trouble.
